Problem

It's currently maintained in our Postgres forks, and we are approaching 5 of them (PG 14-18) this year, so more code creates an additional maintenance overhead.

Proposal

Move this code to the extension and replace the Postgres part with hooks.

We had a very old attempt to approach it: #3193. It probably doesn't make much sense to try to revive it and rebase, as there have been too many changes since then, but it might be good to grasp the idea.