None of the other store classes use the `Matrix` prefix, and I find the mismatch
confusing (it leads me to think it might have a different purpose than the
others).
This change removes the prefix from the store for consistency. The old name is
left as an export for existing SDK consumers.
for some small rooms, it is possible that calling /members would not
yield any previously unknown members, as they were all recently active.
This would be the case for most DMs.
For these rooms, we'd end up with 0 OOB members after lazy loading them,
so when getting them out of storage we need a way to distuinguist this case
from never having lazy loaded the members of the room at all.
We store a marker object in the same store and return [] or null accordingly.
This way the /members don't get fetched a second time.
1. Fix double 'loaded' on sync data logging
2. Move the 'loaded' message into the bit where the data has
actually loaded rather than the promise try block.
3. Add '...' to the 'loading' messages so they're easier to tell
apart from the 'loaded' messages.
Remove the call to /keys/changes when we do an incremental syn
where the old sync token doesn't match the one in the device list
store. To allow us to do this, always save the device list store
before saving the sync data, so we can safely assume the device
list store is at least as fresh as the sync token in the sync store.
Thread save functions through to allow this, add a delay parameter
so the sync can save the device list immediately and skip the wait,
and add a wantsSave() method so the sync can skip saving the device
list if the sync store isn't going to save anyway.
Fixes https://github.com/vector-im/riot-web/issues/6068
