Add vtctldclient missing cmds

[mattlord]

Description

This implements client commands in vtctldclient that were never ported during the client migration. These are things that were identified while moving all endtoend tests to use vtctldclient exclusively in #17441. The missing commands being:

• CopySchemaShard
• ValidatePermissionsKeyspace
• ValidatePermissionsShard
• ValidateSchemaShard
• WriteTopologyPath

We will (after merging in main once #17441 is merged) also then replace all remaining vtctlclient usage in the e2e tests with usage of these new vtctldclient commands.

Related Issue(s)

• Follow-up to: Move all e2e tests to vtctldclient #17441

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

• Apply the release notes (needs details) label if users need to know about this change.
• New features should be documented.
• There should be some code comments as to why things are implemented the way they are.
• There should be a comment at the top of each new or modified test to explain what the test does.

New flags

• Is this flag really necessary?
• Flag names must be clear and intuitive, use dashes (-), and have a clear help text.

If a workflow is added or modified:

• Each item in Jobs should be named in order to mark it as required.
• If the workflow needs to be marked as required, the maintainer team must be notified.

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 10.71429% with 300 lines in your changes missing coverage. Please review.

Project coverage is 67.59%. Comparing base (059d01a) to head (f0047fa).
Report is 10 commits behind head on main.

Files with missing lines	Patch %	Lines
go/cmd/vtctldclient/command/schema.go	13.86%	118 Missing ⚠️
go/vt/vtctl/grpcvtctldserver/server.go	7.76%	95 Missing ⚠️
go/cmd/vtctldclient/command/permissions.go	8.51%	43 Missing ⚠️
go/cmd/vtctldclient/command/topology.go	14.28%	30 Missing ⚠️
go/vt/vtctl/grpcvtctldclient/client_gen.go	0.00%	10 Missing ⚠️
go/vt/vtctl/localvtctldclient/client_gen.go	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #17442      +/-   ##
==========================================
- Coverage   67.68%   67.59%   -0.09%     
==========================================
  Files        1583     1585       +2     
  Lines      254321   254632     +311     
==========================================
- Hits       172131   172126       -5     
- Misses      82190    82506     +316     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.