Full roomserver input transactional isolation (#2141)

* Add transaction to all database tables in roomserver, rename latest events updater to room updater, use room updater for all RS input

* Better transaction management

* Tweak order

* Handle cases where the room does not exist

* Other fixes

* More tweaks

* Fill some gaps

* Fill in the gaps

* good lord it gets worse

* Don't roll back transactions when events rejected

* Pass through errors properly

* Fix bugs

* Fix incorrect error check

* Don't panic on nil txns

* Tweaks

* Hopefully fix panics for good in SQLite this time

* Fix rollback

* Minor bug fixes with latest event updater

* Some review comments

* Revert "Some review comments"

This reverts commit 0caf8cf53e62c33f7b83c52e9df1d963871f751e.

* Fix a couple of bugs

* Clearer commit and rollback results

* Remove unnecessary prepares

roomserver/internal/input/input_membership.go

@@ -31,7 +31,7 @@ import (
 // consumers about the invites added or retired by the change in current state.
 func (r *Inputer) updateMemberships(
 	ctx context.Context,
-	updater *shared.LatestEventsUpdater,
+	updater *shared.RoomUpdater,
 	removed, added []types.StateEntry,
 ) ([]api.OutputEvent, error) {
 	changes := membershipChanges(removed, added)
@@ -79,7 +79,7 @@ func (r *Inputer) updateMemberships(
 }
 
 func (r *Inputer) updateMembership(
-	updater *shared.LatestEventsUpdater,
+	updater *shared.RoomUpdater,
 	targetUserNID types.EventStateKeyNID,
 	remove, add *gomatrixserverlib.Event,
 	updates []api.OutputEvent,