Add linearizable support to SQL VSchema management

[mattlord]

Description

This PR prevents lost writes when using the VTGate SQL API for VSchema management (see issue).

It also lays the foundation for supporting linearizability guarantees for vschemas within Vitess. Please see the tracking issue for the other known pieces.

Related Issue(s)

• Fixes: Add versioning to the low level topo interface for VSchemas using the existing Info struct model #17399
• Fixes: Bug Report: Update VSchema not send version if there are multiple vtgates operating at the same time. #15794
• Part of: Tracking Issue: Make VSchema management linearizable #17398

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

[vitess-bot]

Review Checklist

Hello reviewers! 👋 Please follow this checklist when reviewing this Pull Request.

General

• Ensure that the Pull Request has a descriptive title.
• 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

• Bug fixes should have at least one unit or end-to-end test, enhancement and new features should have a sufficient number of tests.

Documentation

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Backward compatibility

• Protobuf changes should be wire-compatible.
• Changes to _vt tables and RPCs need to be backward compatible.
• RPC changes should be compatible with vitess-operator
• If a flag is removed, then it should also be removed from vitess-operator and arewefastyet, if used there.
• vtctl command output order should be stable and awk-able.

[codecov]

Codecov Report

Attention: Patch coverage is 75.00000% with 65 lines in your changes missing coverage. Please review.

Project coverage is 67.70%. Comparing base (71ccd6d) to head (d8c9c53).

Files with missing lines	Patch %	Lines
go/vt/vtctl/vtctl.go	31.25%	22 Missing ⚠️
go/vt/vtgate/executorcontext/vcursor_impl.go	60.00%	8 Missing ⚠️
go/cmd/vtcombo/cli/vschema_watcher.go	0.00%	7 Missing ⚠️
go/vt/topotools/vschema_ddl.go	86.04%	6 Missing ⚠️
go/vt/vtcombo/tablet_map.go	0.00%	5 Missing ⚠️
go/vt/topo/vschema.go	90.00%	4 Missing ⚠️
go/vt/vtctl/grpcvtctldserver/server.go	85.71%	4 Missing ⚠️
go/vt/vtgate/vschema_manager.go	55.55%	4 Missing ⚠️
go/vt/topo/helpers/copy.go	33.33%	2 Missing ⚠️
go/test/utils/diff.go	0.00%	1 Missing ⚠️
... and 2 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #17401      +/-   ##
==========================================
- Coverage   67.71%   67.70%   -0.02%     
==========================================
  Files        1584     1584              
  Lines      254721   254799      +78     
==========================================
+ Hits       172473   172499      +26     
- Misses      82248    82300      +52     

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