sql,schemachanger: disallow dropping indexes when referenced in UDF/View

[Xiang-Gu]

This PR disallows schema changes (in both legacy and declarative schema changers) that would drop indexes referenced explicitly via index hinting in UDF or view. They include DROP INDEX, ADD COLUMN, DROP COLUMN, and ALTER PRIMARY KEY.

Fixes #108974
Epic: None
Release note: None

[cockroach-teamcity]

This change is 

[Xiang-Gu]

This is ready for a look. CI failure is due to flaky tests unrelated to this PR.

[fqazi]

A couple of minor comments but

Reviewed 9 of 9 files at r1, 6 of 6 files at r2, all commit messages.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @lidorcarmel and @Xiang-Gu)

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-- commits line 5 at r1:
minor typo

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pkg/sql/rename_table.go line 311 at r1 (raw file):

		viewName = viewFQName.FQString()
	}
	return sqlerrors.NewDependingObjBlocksOpError(op, typeName, objName, "view", viewName)

Could we call this NewDependentBlocksOpError instead?

[Xiang-Gu]

TFTR!

bors r+

Reviewable status: complete! 0 of 0 LGTMs obtained (and 1 stale) (waiting on @fqazi and @lidorcarmel)

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pkg/sql/rename_table.go line 311 at r1 (raw file):

Previously, fqazi (Faizan Qazi) wrote…

Could we call this NewDependentBlocksOpError instead?

Done.

[craig]

🕐 Waiting for PR status (GitHub check) to be set, probably by CI. Bors will automatically try to run when all required PR statuses are set.

[craig]

Build succeeded:

• Bazel Essential CI (Cockroach)

[rafiss]

blathers backport 23.1

[blathers-crl]

Encountered an error creating backports. Some common things that can go wrong:

1. The backport branch might have already existed.
2. There was a merge conflict.
3. The backport branch contained merge commits.

You might need to create your backport manually using the backport tool.

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error creating merge commit from dcb2acf to blathers/backport-release-23.1-109611: POST https://api.github.com/repos/cockroachdb/cockroach/merges: 409 Merge conflict []

you may need to manually resolve merge conflicts with the backport tool.

Backport to branch 23.1 failed. See errors above.

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