[dattri.algorithm] Re-add RPS attributor

[tingwl0122]

Description

This PR implements the Representer Point Selection Attributor as another data attribution algorithm.

1. Motivation and Context

To migrate the official RPS implementation into our context. This PR will close #57 .

2. Summary of the change

• re-add RPSAttributor and several helper functions to algorithm/utils
• add a test file to test RPS functionality
• modify function in model_utils/hook
• modify the test function for model_utils/hook

3. What tests have been added/updated for the change?

• [x] Unit test: Typically, this should be included if you implemented a new function/fixed a bug.

[jiaqima]

Also update dattri/docs/source/api/algorithm.rst?

[tingwl0122]

Also update dattri/docs/source/api/algorithm.rst?

updated.

[TheaperDeng]

LGTM.