Foreign Key: Add support for multi target delete

[harshit-gangal]

Description

This PR adds support for multi-target delete with foreign key constraints

Related Issue(s)

• RFC: Foreign Key Support in Vitess #12967

Checklist

• 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

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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 81.81818% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 65.72%. Comparing base (696fe0e) to head (15f57ba).
Report is 129 commits behind head on main.

Files	Patch %	Lines
go/vt/vtgate/planbuilder/operators/delete.go	83.33%	1 Missing ⚠️
go/vt/vtgate/semantics/semantic_state.go	80.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #15504      +/-   ##
==========================================
- Coverage   67.41%   65.72%   -1.70%     
==========================================
  Files        1560     1560              
  Lines      192752   194455    +1703     
==========================================
- Hits       129952   127806    -2146     
- Misses      62800    66649    +3849     

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