Add TMC RPCs for updating sequences for switchwrites

[beingnoble03]

Description

This PR adds 2 TMC RPCs:

• GetMaxValueForSequences : Gets the max used sequence value mapped with the provided backing sequence tables.
• UpdateSequenceTables: Updates all the sequence tables listed in the request, with the max value provided in the sequence metadata.

Instead of separate RPC calls for each table per shard, these 2 RPCs allow it to reduce to just 1 RPC call (all tables at once) per shard for fetching and updating max sequence value each.

Related Issue(s)

• SwitchWrites: improve performance of sequence initialisation steps #17871

Checklist

• "Backport to:" labels have been added if this change should be back-ported to release branches
• If this change is to be back-ported to previous releases, a justification is included in the PR description
• Tests were added or are not required
• Did the new or modified tests pass consistently locally and on CI?
• Documentation was added or is not required

Deployment Notes

[vitess-bot]

Review Checklist

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General

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• Ensure there is a link to an issue (except for internal cleanup and flaky test fixes), new features should have an RFC that documents use cases and test cases.

Tests

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Backward compatibility

• Protobuf changes should be wire-compatible.
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[codecov]

Codecov Report

Attention: Patch coverage is 21.60804% with 156 lines in your changes missing coverage. Please review.

Project coverage is 67.50%. Comparing base (6b88ff2) to head (d1ff7e5).
Report is 18 commits behind head on main.

Files with missing lines	Patch %	Lines
go/vt/vttablet/tabletmanager/rpc_vreplication.go	0.00%	104 Missing ⚠️
go/vt/vtctl/workflow/sequences.go	75.43%	14 Missing ⚠️
go/vt/vttablet/grpctmclient/client.go	0.00%	14 Missing ⚠️
go/vt/vttablet/grpctmserver/server.go	0.00%	10 Missing ⚠️
go/vt/vttablet/tmrpctest/test_tm_rpc.go	0.00%	6 Missing ⚠️
go/vt/vtcombo/tablet_map.go	0.00%	4 Missing ⚠️
go/vt/vttablet/faketmclient/fake_client.go	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #18172      +/-   ##
==========================================
- Coverage   67.55%   67.50%   -0.06%     
==========================================
  Files        1601     1601              
  Lines      261424   261576     +152     
==========================================
- Hits       176599   176570      -29     
- Misses      84825    85006     +181     

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[rohit-nayak-ps]

Let's add a comment here about what this map's key is.

[beingnoble03]

done.