## Summary
If parent violates LSP against grandparent, and child has the same
violation (but matches parent), we no longer flag the LSP violation on
child, since it can't be fixed without violating parent.
If parent violates LSP against grandparent, and child violates LSP
against both parent and grandparent, we emit two diagnostics (one for
each violation).
If parent violates LSP against grandparent, and child violates LSP
against parent (but not grandparent), we flag it.
Closes https://github.com/astral-sh/ty/issues/2000.
When converting a class (whether specialized or not) into a `Callable`
type, we should carry through any generic context that the constructor
has. This includes both the generic context of the class itself (if it's
generic) and of the constructor methods (if they are separately
generic).
To help test this, this also updates the `generic_context` extension
function to work on `Callable` types and unions; and adds a new
`into_callable` extension function that works just like
`CallableTypeOf`, but on value forms instead of type forms.
Pulled this out of #21551 for separate review.
## Summary
Building on https://github.com/astral-sh/ruff/pull/21436.
There's nothing conceptually more complicated about this, it just
requires its own set of tests and its own subdiagnostic hint.
I also uncovered another inconsistency between mypy/pyright/pyrefly,
which is fun. In this case, I suggest we go with pyright's behaviour.
## Test Plan
mdtests/snapshots
