[red-knot] Migrate is_subtype_of unit tests to Markdown tests (#15469)

## Summary

Part of #15397.

## Test Plan

Markdown tests.

---------

Co-authored-by: David Peter <mail@david-peter.de>

crates/red_knot_python_semantic/resources/mdtest/type_properties/is_subtype_of.md

@@ -0,0 +1,238 @@
+# Subtype relation
+
+## Basic types
+
+```py
+from typing_extensions import Literal
+from knot_extensions import is_subtype_of, static_assert
+
+static_assert(is_subtype_of(str, object))
+static_assert(is_subtype_of(int, object))
+static_assert(is_subtype_of(bool, object))
+
+static_assert(is_subtype_of(bool, int))
+static_assert(is_subtype_of(TypeError, Exception))
+static_assert(is_subtype_of(FloatingPointError, Exception))
+
+static_assert(not is_subtype_of(object, int))
+static_assert(not is_subtype_of(int, str))
+static_assert(not is_subtype_of(int, Literal[1]))
+
+static_assert(not is_subtype_of(Literal[1], str))
+static_assert(not is_subtype_of(Literal[1, 2], Literal[1]))
+static_assert(not is_subtype_of(Literal[1, 2], Literal[1, 3]))
+```
+
+## Non-fully-static types
+
+`Any`, `Unknown`, `Todo` and derivatives thereof do not participate in subtyping.
+
+```py
+from typing import Any
+from typing_extensions import Literal
+from knot_extensions import Unknown, is_subtype_of, static_assert
+
+static_assert(not is_subtype_of(Unknown, Unknown))
+static_assert(not is_subtype_of(Unknown, Literal[1]))
+static_assert(not is_subtype_of(Literal[1], Unknown))
+
+static_assert(not is_subtype_of(Any, Any))
+static_assert(not is_subtype_of(Any, Literal[1]))
+
+static_assert(not is_subtype_of(Literal[1], Any))
+static_assert(not is_subtype_of(Literal[1], Unknown | str))
+```
+
+## `Never`
+
+`Never` is a subtype of all types.
+
+```py
+from typing_extensions import Literal, Never
+from knot_extensions import AlwaysTruthy, AlwaysFalsy, is_subtype_of, static_assert
+
+static_assert(is_subtype_of(Never, Literal[1]))
+
+static_assert(is_subtype_of(Never, AlwaysTruthy))
+static_assert(is_subtype_of(Never, AlwaysFalsy))
+```
+
+## Literal types
+
+```py
+from typing_extensions import Literal, LiteralString
+from knot_extensions import is_subtype_of, static_assert
+
+static_assert(is_subtype_of(Literal[1], int))
+static_assert(is_subtype_of(Literal[1], object))
+
+static_assert(is_subtype_of(Literal[True], bool))
+static_assert(is_subtype_of(Literal[True], int))
+static_assert(is_subtype_of(Literal[True], object))
+
+static_assert(is_subtype_of(Literal["foo"], LiteralString))
+static_assert(is_subtype_of(Literal["foo"], str))
+static_assert(is_subtype_of(Literal["foo"], object))
+
+static_assert(is_subtype_of(LiteralString, str))
+static_assert(is_subtype_of(LiteralString, object))
+
+static_assert(is_subtype_of(Literal[b"foo"], bytes))
+static_assert(is_subtype_of(Literal[b"foo"], object))
+```
+
+## Tuple types
+
+```py
+from typing_extensions import Literal, Any
+from knot_extensions import is_subtype_of, static_assert
+
+static_assert(is_subtype_of(tuple[()], tuple[()]))
+static_assert(is_subtype_of(tuple[Literal[42]], tuple[int]))
+static_assert(is_subtype_of(tuple[Literal[42], Literal["foo"]], tuple[int, str]))
+static_assert(is_subtype_of(tuple[int, Literal["foo"]], tuple[int, str]))
+static_assert(is_subtype_of(tuple[Literal[42], str], tuple[int, str]))
+
+static_assert(not is_subtype_of(tuple[()], tuple[Literal[1]]))
+static_assert(not is_subtype_of(tuple[Literal[42]], tuple[str]))
+
+static_assert(not is_subtype_of(tuple[Any], tuple[Literal[2]]))
+static_assert(not is_subtype_of(tuple[Literal[2]], tuple[Any]))
+```
+
+## Union types
+
+```py
+from typing_extensions import Literal
+from knot_extensions import is_subtype_of, static_assert
+
+static_assert(is_subtype_of(Literal[1], int | str))
+static_assert(is_subtype_of(str | int, object))
+static_assert(is_subtype_of(Literal[1, 2], Literal[1, 2, 3]))
+```
+
+## Intersection types
+
+```py
+from typing_extensions import Literal, LiteralString
+from knot_extensions import Intersection, Not, is_subtype_of, static_assert
+
+static_assert(is_subtype_of(Intersection[int, Not[Literal[2]]], int))
+static_assert(is_subtype_of(Intersection[int, Not[Literal[2]]], Not[Literal[2]]))
+static_assert(is_subtype_of(Not[int], Not[Literal[2]]))
+static_assert(is_subtype_of(Literal[1], Intersection[int, Not[Literal[2]]]))
+static_assert(is_subtype_of(Intersection[str, Not[Literal["foo"]]], Not[Literal[2]]))
+static_assert(is_subtype_of(Not[LiteralString], object))
+
+static_assert(is_subtype_of(type[str], Not[None]))
+static_assert(is_subtype_of(Not[LiteralString], object))
+
+static_assert(not is_subtype_of(Intersection[int, Not[Literal[2]]], Intersection[int, Not[Literal[3]]]))
+static_assert(not is_subtype_of(Not[Literal[2]], Not[Literal[3]]))
+static_assert(not is_subtype_of(Not[Literal[2]], Not[int]))
+
+static_assert(not is_subtype_of(int, Not[Literal[3]]))
+static_assert(not is_subtype_of(Literal[1], Intersection[int, Not[Literal[1]]]))
+```
+
+## Class literal types
+
+```py
+from types import ModuleType
+from typing import _SpecialForm
+from typing_extensions import Literal, LiteralString
+import typing
+from knot_extensions import TypeOf, is_subtype_of, static_assert
+
+class Meta(type): ...
+class HasCustomMetaclass(metaclass=Meta): ...
+
+static_assert(is_subtype_of(TypeOf[bool], type[int]))
+static_assert(is_subtype_of(TypeOf[int], TypeOf[int]))
+static_assert(is_subtype_of(TypeOf[int], object))
+
+static_assert(is_subtype_of(TypeOf[Literal], _SpecialForm))
+static_assert(is_subtype_of(TypeOf[Literal], object))
+
+static_assert(is_subtype_of(TypeOf[HasCustomMetaclass], Meta))
+static_assert(is_subtype_of(Meta, type[object]))
+static_assert(not is_subtype_of(Meta, type[type]))
+
+static_assert(is_subtype_of(tuple[int], tuple))
+static_assert(is_subtype_of(TypeOf[str], type))
+
+static_assert(is_subtype_of(TypeOf[typing], ModuleType))
+static_assert(is_subtype_of(TypeOf[1:2:3], slice))
+
+static_assert(not is_subtype_of(type, type[int]))
+static_assert(not is_subtype_of(TypeOf[str], type[Any]))
+static_assert(not is_subtype_of(type[str], TypeOf[str]))
+
+static_assert(not is_subtype_of(TypeOf[int], TypeOf[object]))
+static_assert(not is_subtype_of(TypeOf[int], int))
+
+static_assert(not is_subtype_of(_SpecialForm, TypeOf[Literal]))
+```
+
+## `AlwaysTruthy` and `AlwaysFalsy`
+
+```py
+from knot_extensions import AlwaysTruthy, AlwaysFalsy, is_subtype_of, static_assert
+
+static_assert(is_subtype_of(Literal[1], AlwaysTruthy))
+static_assert(is_subtype_of(Literal[0], AlwaysFalsy))
+
+static_assert(is_subtype_of(AlwaysTruthy, object))
+static_assert(is_subtype_of(AlwaysFalsy, object))
+
+static_assert(not is_subtype_of(Literal[1], AlwaysFalsy))
+static_assert(not is_subtype_of(Literal[0], AlwaysTruthy))
+
+static_assert(not is_subtype_of(str, AlwaysTruthy))
+static_assert(not is_subtype_of(str, AlwaysFalsy))
+```
+
+## Unions
+
+```py
+from typing_extensions import assert_type
+from knot_extensions import TypeOf, is_subtype_of, static_assert
+
+class Base: ...
+class Derived(Base): ...
+class Unrelated: ...
+
+type LiteralBase = TypeOf[Base]
+type LiteralDerived = TypeOf[Derived]
+type LiteralUnrelated = TypeOf[Unrelated]
+
+assert_type(Base, LiteralBase)
+assert_type(Derived, LiteralDerived)
+assert_type(Unrelated, LiteralUnrelated)
+
+static_assert(is_subtype_of(LiteralBase, type))
+static_assert(is_subtype_of(LiteralBase, object))
+
+static_assert(is_subtype_of(LiteralBase, type[Base]))
+static_assert(is_subtype_of(LiteralDerived, type[Base]))
+static_assert(is_subtype_of(LiteralDerived, type[Derived]))
+
+static_assert(not is_subtype_of(LiteralBase, type[Derived]))
+static_assert(is_subtype_of(type[Derived], type[Base]))
+
+static_assert(is_subtype_of(LiteralBase | LiteralUnrelated, type))
+static_assert(is_subtype_of(LiteralBase | LiteralUnrelated, object))
+```
+
+## Intersections
+
+```py
+from knot_extensions import Intersection, is_subtype_of, static_assert
+
+class A: ...
+class B: ...
+
+static_assert(not is_subtype_of(A, B))
+static_assert(is_subtype_of(Intersection[A, B], A))
+static_assert(is_subtype_of(Intersection[A, B], B))
+```