This makes each reply chain load completely before loading the next
chain, instead of the current behavior that loads all replies of one
depth before loading the next "layer".
This won't make much of a difference *now*, but should result in more
intuitive behavior when live updating of newly loaded replies gets
implemented.
This was caused because of an inconsistency of whether to set the account domain as a fallback value or not. Therefore, invocations with the mentioned local user host not having a fallback value would cause broken mention rendering, e.g. in bios/profile fields.
This bug caused followers-only announce activities to be saved as specified when the activity actor was not inlined (which it is not in most cases), and the followers collection URI is not the well-known one.
Instead of backfilling every note we come across that has a reply
collection, only schedule a backfill job if someone wants to see the
replies (on GET MastoAPI /context, or Iceshrimp API /descendants)
Reply backfilling is also done on a ThreadIdOrId basis as opposed to the
previous way of backfilling individual notes. This allows us finer
grained control over the recursion and frees up the job queue, alongside
allowing for easier implementation of context collection backfill in the
future (by mapping each context collection to a thread)
---
Currently, note threads are implicit based on the "threadId" column of a
note, which can be null (where it's the same as the note's "id")
This commit turns note threads into an actual entity, and as a part of
that, makes "threadId" non-nullable (by specifically setting it to "id"
for those cases)
This is done to attach extra metadata to the entire thread, currently
just the time of when it was last backfilled, but more may be added in
the future (the context collection associated with this thread, for example)
---
The data format for backfill jobs have backwards-incompatibly changed
since the introduction of the feature. We can drop all old jobs without
causing too much trouble as they will be re-scheduled on demand
---
Signed-off-by: Laura Hausmann <laura@hausmann.dev>
