RUM-4098: Use the datastore for Session Replay resources

[jonathanmos]

What does this PR do?

Use the datastore from Session Replay, so that resource hashes are persisted between sessions.

Motivation

The second part of the effort to persist bitmap hashes between sessions.

Additional Notes

Anything else we should know when reviewing?

Review checklist (to be filled by reviewers)

• [ ] Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• [ ] Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• [ ] Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)