planner: add variable tidb_enable_inl_join_inner_multi_pattern (#13451)

[ti-chi-bot]

This is an automated cherry-pick of #13451

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What is changed, added or deleted? (Required)

Add a new variable tidb_enable_inl_join_inner_multi_pattern to control whether the inner table of Index Join supports Selection or Projection operators.

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What is the related PR or file link(s)?

• This PR is translated from:
• Other reference link(s):
  planner: support more pattern for index join inner side tidb#40999
  sysvar: introduce variable tidb_enable_inl_join_inner_multi_pattern tidb#41319

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• Delete files
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[ti-chi-bot]

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• ran-huang

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[Oreoxmt]

@chrysan @ran-huang PTAL

[Oreoxmt]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 83aa9a1