release-23.2: sql: support sequence and udt name rewriting in plpgsql

[rharding6373]

Backport 1/1 commits from #115809.

/cc @cockroachdb/release

---

CRDB rewrites sequence and UDT names as IDs in views and functions so
that if the sequence or UDT is renamed the views and functions using
them don't break. This PR adds support for this in PLpgSQL.

Epic: None
Fixes: #115627

Release note: Fixes a bug in PLpgSQL where altering the name of a
sequence or UDT that was used in a PLpgSQL function or procedure could
break them. This is only present in 23.2 alpha and beta releases.

Release justification: Fixes a bug in PLpgSQL that could result in breaking PLpgSQL functions if sequences or UDTs are renamed.

[blathers-crl]

Thanks for opening a backport.

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[blathers-crl]

Your pull request contains more than 1000 changes. It is strongly encouraged to split big PRs into smaller chunks.

_{🦉 Hoot! I am a Blathers, a bot for CockroachDB. My owner is dev-inf.}

[cockroach-teamcity]

This change is 

[rharding6373]

Needs #116423 as a prereq.

[rytaft]

Adding @rafiss as second TL reviewer

[rharding6373]

TFTRs!