[RLlib] Better support MultiBinary spaces by treating Tuples as superset of them in ComplexInputNet

[ArturNiederfahrenhorst]

Signed-off-by: Artur Niederfahrenhorst artur@anyscale.com

Why are these changes needed?

This PR solves two issues that are both encapsulated in the issue referred below. Both issues are with the ComplexInputNet.

1. If a component of an obs space has three dimensions, we assume it's an image (this only makes sense for a Box)
2. We don't represent the MultiBinary space (which is closely related to a Tuple). I argue that it's easier to simply treat MultiBinary as a Tuple than telling users to use Tuples.

Related issue number

Closes #28605

Checks

• I've signed off every commit(by using the -s flag, i.e., git commit -s) in this PR.
• 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
  • Unit tests
  • Release tests
  • This PR is not tested :(

[cool-RR]

Do any code owners have time to review this?

[ArturNiederfahrenhorst]

Before they review there is a test that's failing. I'll have to have another look at it soon!

[stale]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

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[stale]

Hi again! The issue will be closed because there has been no more activity in the 14 days since the last message.

Please feel free to reopen or open a new issue if you'd still like it to be addressed.

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Thanks again for opening the issue!

[sven1977]

LGTM.