Redis cache support for enrichment transform

[riteshghorse]

This PR implements Redis caching support for RequestResponseIO and integrates it with Enrichment transform. It also enables the test for RRIO and Enrichment with HTTP Mock API.

Part of #29787

---

Thank you for your contribution! Follow this checklist to help us incorporate your contribution quickly and easily:

• Mention the appropriate issue in your description (for example: addresses #123), if applicable. This will automatically add a link to the pull request in the issue. If you would like the issue to automatically close on merging the pull request, comment fixes #<ISSUE NUMBER> instead.
• Update CHANGES.md with noteworthy changes.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

See the Contributor Guide for more tips on how to make review process smoother.

To check the build health, please visit https://github.com/apache/beam/blob/master/.test-infra/BUILD_STATUS.md

GitHub Actions Tests Status (on master branch)

See CI.md for more information about GitHub Actions CI or the workflows README to see a list of phrases to trigger workflows.

[github-actions]

Assigning reviewers. If you would like to opt out of this review, comment assign to next reviewer:

R: @tvalentyn for label python.
R: @damccorm for label build.
R: @chamikaramj for label io.

Available commands:

• stop reviewer notifications - opt out of the automated review tooling
• remind me after tests pass - tag the comment author after tests pass
• waiting on author - shift the attention set back to the author (any comment or push by the author will return the attention set to the reviewers)

The PR bot will only process comments in the main thread (not review comments).

[riteshghorse]

Redis cache tests passed

Failing ones are the older RRIO tests with HTTP (although enrichment tests for HTTP are passing) due to a problem with urllib3. I'll check.

[riteshghorse]

This passed

And I think found the problem with other RRIO test as well :)

[damccorm]

Haven't gotten through the tests yet, but on the whole this looks pretty good to me; left some comments

[damccorm]

Nit: I think this logic is shared and can be extracted out of the if/else

[riteshghorse]

The write part is similar but it has tuples as input

[damccorm]

Had one small nit, otherwise this looks good to me once tests pass

[riteshghorse]

Thank you both Danny and Valentyn for your reviews!

[riteshghorse]

Thanks @tvalentyn! Made changes from some of your suggestions but kept a few of them as is. If this looks good I'll drop the postcommit file once tests pass and merge. Thanks!

[riteshghorse]

I'm removing this test

Since this failure is not reproducible locally and fails with a different error everytime - it was throwing this earlier

and we already have 3 other tests passing for testing the RRIO with MockAPI.

[riteshghorse]

@tvalentyn I ended up using the @property for setters. Thanks again for the suggestions!

All tests passed. Dropping the postcommit file