[flake8-type-checking] Improve flexibility of runtime-evaluated-decorators (#15204)

Co-authored-by: Micha Reiser <micha@reiser.io>

crates/ruff_python_ast/src/name.rs

@@ -277,6 +277,14 @@ impl<'a> QualifiedName<'a> {
         inner.push(member);
         Self(inner)
     }
+
+    /// Extends the qualified name using the given members.
+    #[must_use]
+    pub fn extend_members<T: IntoIterator<Item = &'a str>>(self, members: T) -> Self {
+        let mut inner = self.0;
+        inner.extend(members);
+        Self(inner)
+    }
 }
 
 impl Display for QualifiedName<'_> {