[RLlib] Add filters to connector pipeline

[ArturNiederfahrenhorst]

Why are these changes needed?

In our efforts to include our diverse experience processing steps into the connector pipeline, this PR includes filters. As long as connectors can be switched off, we have to support the old and new place for filters and this PR thus tried to find a path that enables both by still indexing the filters alt RolloutWorker().policy_map[<policy_id>].filter and updating them there, while instantiating them in the AgentConnectors of a policy.

Checks

• [x] I've signed off every commit(by using the -s flag, i.e., git commit -s) in this PR.
• [x] I've run scripts/format.sh to lint the changes in this PR.
• [ ] I've included any doc changes needed for https://docs.ray.io/en/master/.
• [ ] I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • [x] Unit tests
  • [ ] Release tests
  • [ ] This PR is not tested :(

[gjoliver]

how did you merge master? something is weird, your PR has 728 files :) I usually do git rebase master in the branch after you pull master.

[ArturNiederfahrenhorst]

Absolutely. I simply copied the steps recommended by our "DCO failed Details" page without thinking much about what would be rebased here. Seems that a lot of changes from master got rebased here.

[ArturNiederfahrenhorst]

I'll leave this as it is for a couple of hours so that we can decide if we want to change the steps recommended by the DCO page.