feat(meta): inform executors of the vnodes they own

[xx01cyx]

What's changed and what's your intention?

Summarize your change

• Set vnodes into StreamActor proto in meta. Executors in one actor share the same set of vnodes, so in this way, stream executors can know the vnodes they own.
• Add some comments about the logic of schedule().

Checklist

• I have written necessary docs and comments
• I have added necessary unit tests and integration tests

Refer to a related PR or issue link

This PR should work with #2882 to enable vnode pruning. Specifically, a stateful executor should use the vnode info it gets from meta in this PR to initialize its keyspace.

[codecov]

Codecov Report

Merging #2887 (9da70b4) into main (c51c094) will decrease coverage by 0.00%.
The diff coverage is 72.36%.

@@            Coverage Diff             @@
##             main    #2887      +/-   ##
==========================================
- Coverage   72.90%   72.89%   -0.01%     
==========================================
  Files         703      703              
  Lines       93151    93196      +45     
==========================================
+ Hits        67910    67939      +29     
- Misses      25241    25257      +16     

Flag	Coverage Δ
rust	72.89% <72.36%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/common/src/hash/dispatcher.rs	91.89% <ø> (ø)
src/meta/src/cluster/mod.rs	59.58% <ø> (ø)
src/meta/src/hummock/level_handler.rs	73.86% <ø> (ø)
src/meta/src/hummock/test_utils.rs	95.80% <ø> (-0.06%)	⬇️
src/meta/src/stream/meta.rs	37.12% <0.00%> (-0.51%)	⬇️
src/meta/src/stream/mod.rs	40.90% <0.00%> (ø)
src/storage/src/hummock/compactor.rs	68.93% <ø> (ø)
src/storage/src/hummock/shared_buffer/mod.rs	85.30% <ø> (ø)
src/storage/src/hummock/sstable/builder.rs	91.52% <ø> (-0.05%)	⬇️
src/storage/src/hummock/sstable/group_builder.rs	93.75% <ø> (ø)
... and 14 more

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[fuyufjh]

LGTM!