Data Sharing: Periodical checks of content / accounts

[oneiros]

Periodically re-rechecking content and accounts for changes in visibility or discovery opt-in will result in a lot of work for discovery FASP and put additional strain on affected fediverse servers.

We could maybe minimize this with a couple of measures:

• Trust content from connected fediverse servers with an active lifecycle event subscription to be up-to-date.
• Re-Check older objects less frequently (might be tricky to get right)
• Only re-check objects if they are actually returned as part of a search

Also see discussion here: #36 (comment)