[Feature] Add modules.OrnsteinUhlenbeckProcessModule

[kurtamohler]

Description

Add OrnsteinUhlenbeckProcessModule, which serves the same purpose as OrnsteinUhlenbeckProcessWrapper, but derives from TensorDictModuleBase rather than TensorDictModuleWrapper

Motivation and Context

part of #2295

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• New feature (non-breaking change which adds core functionality)
• Documentation (update in the documentation)

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[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/rl/2297

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❌ 11 New Failures, 1 Pending, 2 Unrelated Failures

As of commit 04b1511 with merge base c4b2eb0 ():

NEW FAILURES - The following jobs have failed:

• Continuous Benchmark (PR) / CPU Pytest benchmark (gh)
  Workflow failed! Resource not accessible by integration
• Continuous Benchmark (PR) / GPU Pytest benchmark (gh)
  Workflow failed! Resource not accessible by integration
• Habitat Tests on Linux / tests (3.9, 12.1) / linux-job (gh)
  RuntimeError: Command docker exec -t 498ef97fe4973966b55f9cb0bedc25ed6d6ec9b97a0277e72cb52facd6e46c98 /exec failed with exit code 139
• Unit-tests on Linux / tests-cpu (3.10) / linux-job (gh)
  test/test_rb.py::TestStorages::test_state_dict[TensorStorage-tensorclass]
• Unit-tests on Linux / tests-cpu (3.11) / linux-job (gh)
  test/test_rb.py::TestStorages::test_state_dict[TensorStorage-tensorclass]
• Unit-tests on Linux / tests-cpu (3.8) / linux-job (gh)
  test/test_rb.py::TestStorages::test_state_dict[TensorStorage-tensorclass]
• Unit-tests on Linux / tests-cpu (3.9) / linux-job (gh)
  test/test_rb.py::TestStorages::test_state_dict[TensorStorage-tensorclass]
• Unit-tests on Linux / tests-gpu (3.10, 12.1) / linux-job (gh)
  test/test_rb.py::TestStorages::test_state_dict[TensorStorage-tensorclass]
• Unit-tests on Linux / tests-optdeps (3.10, 12.1) / linux-job (gh)
  test/test_rb.py::TestStorages::test_state_dict[TensorStorage-tensorclass]
• Unit-tests on Linux / tests-stable-gpu (3.10, 11.8) / linux-job (gh)
  test/test_rb.py::TestStorages::test_state_dict[TensorStorage-tensorclass]
• Unit-tests on Windows / unittests-cpu / windows-job (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 128

BROKEN TRUNK - The following jobs failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• Libs Tests on Linux / unittests-gym (3.9, 12.1) / linux-job (gh) (trunk failure)
  AttributeError: module 'torch' has no attribute 'compiler'
• Unit-tests on Linux / tests-olddeps (3.8, 11.6) / linux-job (gh) (trunk failure)
  AttributeError: module 'torch' has no attribute 'compiler'

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[vmoens]

LGTM
nit: Since we want to deprecate the OU wrapper, can you add a deprecation warning? 2 releases from 0.5, so it will be in 0.7!
Thanks!

[vmoens]

Suggested change

	OrnsteinUhlenbeckProcessModule
	OrnsteinUhlenbeckProcessWrapper
	OrnsteinUhlenbeckProcessModule

since we want to deprecate it

[vmoens]

hmm upon reflection, let's keep this one, people may still see it in their code

[kurtamohler]

Yeah I'd think it's typically a good idea to keep the old documentation and only remove it at the point when the deprecated feature is actually removed

[kurtamohler]

I've added the deprecation warning