Collect and cache metadata, run hooks on changes.

Gerrit User 9816 95d66b2723 Update patch set 2 ... Abandoned Patch-set: 2 Status: abandoned Tag: autogenerated:gerrit:abandon Attention: {"person_ident":"Gerrit User 9816 \u003c9816@4a232e18-c5a9-48ee-94c0-e04e7cca6543\u003e","operation":"REMOVE","reason":"Change was abandoned"}		2023-11-30 02:23:40 +00:00
ec91b0f9365a6a6dec100ae1cf42d68e0cfd76e0	Update patch set 2	2023-11-30 02:23:40 +00:00