Moved indexedAt time to record instead of ipld-block

[dholms]

This migration moves the indexedAt time on ipld_block to the relevant record

This makes the migration in #500 much simpler (no need to track indexedAt time) & is also fixes a leaky abstraction - ipld_block is a repo storage concept & record is an indexing layer concept.

[devinivy]

If there's a missing block for a record, I think this could fail when trying to set indexedAt to null. It shouldn't really happen, but there's nothing at the db level preventing it either. Not sure if it's really necessary, but I think the fix would be to do something like this:

  const indexedAtForRecordQb = db
    .selectFrom('ipld_block')
    .whereRef('ipld_block.cid', '=', ref('record.cid'))
    .select('indexedAt')
  await db
    .updateTable('record')
    .set({ indexedAt: indexedAtForRecordQb })
    .whereExists(indexedAtForRecordQb)
    .execute()

[dholms]

ah nice. great point 👌

[devinivy]

Lookin good!