[MPS] Add Python Module Bindings for the MPS backend (#94417)

- This PR is a prerequisite for the upcoming Memory Leak Detection PR.
- Enable global manual seeding via `torch.manual_seed()` + test case
- Add `torch.mps.synchronize()` to wait for MPS stream to finish + test case
- Enable the following python interfaces for MPS:
  `torch.mps.[get_rng_state(), set_rng_state(), synchronize(), manual_seed(), seed()]`
- Added some test cases in test_mps.py
- Added `mps.rst` to document the `torch.mps` module.
- Fixed the failure with `test_public_bindings.py`

Description of new files added:
- `torch/csrc/mps/Module.cpp`: implements `torch._C` module functions for `torch.mps` and `torch.backends.mps`.
- `torch/mps/__init__.py`: implements Python bindings for `torch.mps` module.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/94417
Approved by: https://github.com/albanD

torch/random.py

@@ -39,6 +39,10 @@ def manual_seed(seed) -> torch._C.Generator:
     if not torch.cuda._is_in_bad_fork():
         torch.cuda.manual_seed_all(seed)
 
+    import torch.mps
+    if not torch.mps._is_in_bad_fork():
+        torch.mps.manual_seed(seed)
+
     return default_generator.manual_seed(seed)
 
 
@@ -52,6 +56,10 @@ def seed() -> int:
     if not torch.cuda._is_in_bad_fork():
         torch.cuda.manual_seed_all(seed)
 
+    import torch.mps
+    if not torch.mps._is_in_bad_fork():
+        torch.mps.manual_seed(seed)
+
     return seed