This should transactional snapshot isolation for `/sync` etc requests.
For now we don't use repeatable read due to some odd test failures with
invites.
* bugfix: fix race condition when updating presence via /sync
Previously when presence is updated via /sync, we would send the presence update
asyncly via NATS. This created a race condition:
- If the presence update is processed quickly, the /sync which triggered the presence
update would see an online presence.
- If the presence update was processed slowly, the /sync which triggered the presence
update would see an offline presence.
This is the root cause behind the flakey sytest: 'User sees their own presence in a sync'.
The fix is to ensure we update the database/advance the stream position synchronously
for local users.
* Bugfix for test
* syncapi: use finer-grained interfaces when making the syncapi
* Use specific interfaces for syncapi-roomserver interactions
* Define query access token api for shared http auth code
* Don't create fictitious presence entries for users that don't have any
* Update whitelist, since that test probably shouldn't be passing
* Fix panics
