beartype.door API tests x 8.

This commit by Harvard microscopist and general genius @tlambert03 is
the next in a commit chain repairing currently failing tests pertaining
to the `beartype.door` subpackage, recently implemented by... yup, it's
@tlambert03 strikes again in PR #136. Specifically, this commit improves
coverage by extending unit tests for this subpackage to additionally
test PEP 484- and 585-compliant `{collections.abc,typing}.Type[...]`
type hints against the `beartype.door.TypeHint` API. (*Long-lasting bold holdfast!*)

beartype_test/a00_unit/a60_api/door/test_door.py

@@ -77,6 +77,7 @@ def hint_subhint_cases() -> 'Iterable[Tuple[object, object, bool]]':
         Sequence,
         Sized,
         Tuple,
+        Type,
         NamedTuple,
         Union,
     )
@@ -86,6 +87,8 @@ class MuhThing:
         def muh_method(self):
             ...
 
+    class MuhSubThing(MuhThing):
+        ...
 
     class MuhNutherThing:
         def __len__(self) -> int:
@@ -140,6 +143,12 @@ class MuhTuple(NamedTuple):
         (List[int], List[Any], True),
         (Awaitable, Awaitable[str], False),
         (List[int], List[str], False),
+        # types
+        (Type[int], Type[int], True),
+        (Type[int], Type[str], False),
+        (Type[MuhSubThing], Type[MuhThing], True),
+        (Type[MuhThing], Type[MuhSubThing], False),
+        (MuhThing, Type[MuhThing], False),
         # maps
         (dict, Dict, True),
         (Dict[str, int], Dict, True),