Add jsonb_ops/jsonb_path_ops indexes on `storage.objects.metadata` & `storage.objects.user_metadata`

[soedirgo]

Originally posted on https://github.com/orgs/supabase/discussions/34270#discussioncomment-13454929

With access to creating indexes gone on storage.objects, could y'all at least add some basic ones to make custom functionality less bad, like jsonb_ops or jsonb_path_ops indexes on the metadata and user_metadata columns?

We have user_metadata values set on S3 API uploads that are used for later query filtering, as well as filtering on metadata values like size and mimetype. The whole storage experience is fairly cumbersome and un-integrated in the first place, so we specifically wanted to avoid having another table needing to be kept in sync with the files.