[Ray] Ray execution state

[fyrestone]

What do these changes do?

Mars execution context provides remote object to sync states between multiple running operands. Ray execution backends use a task state actor for this feature.

With this PR, ray backend supports incremental index.

• Move the logic of initializing context (the ThreadedServiceContext used in the supervisor) to the execution backend.
• Add a task state actor to Ray execution backend.
• Ray execution context supports remote object.
• Not to fetch the chunk meta when tiling HeadOptimizedDataSource.

The drawback is that,

• Poor performance to sync states among operands, maybe we can avoid using remote object when executing operands in the future.
• Hard to fault tolerance because the remote object makes the operands stateful.

Related issue number

#2893

Check code requirements

• tests added / passed (if needed)
• Ensure all linting tests pass, see here for how to run them

[chaokunyang]

Will this ray actor influence the lineage reconstruction in #2972:

1. If this actor died, will lineage reconstruction still succeed?
2. If this actor restarted by ray, how the state auto recovered?
3. If the lineage reconstruction call this actor multiple times, how the idempotence be ensured?

[fyrestone]

Will this ray actor influence the lineage reconstruction in #2972:

1. If this actor died, will lineage reconstruction still succeed?
2. If this actor restarted by ray, how the state auto recovered?
3. If the lineage reconstruction call this actor multiple times, how the idempotence be ensured?

Currently, some operands use a remote object to sync states. If the state actor is reconstructed, the simplest way to recover the compute is,

1. If call remote object can't find the remote object and the state actor is reconstructed, then raises a RecoveryFailed exception.
2. The fault recovery logic catch this exception to recompute the predecessors.

We should make the operands stateless to avoid above complex recovery.

This PR is to maximize compatibility with existing Mars execution logic, the fault recovery is not included in this PR.

[qinxuye]

LGTM

[qinxuye]

@chaokunyang could you please review this PR?

[zhongchun]

LGTM. I left two comments where i am a little confused.

[zhongchun]

LGTM