Fix membership count for BulkPushRuleEvaluator

Don't cache events in _state_group_cache

Make stateGroupCache honour CACHE_SIZE_FACTOR

Instead, simply cache the event ids, relying on the event cache to cache
the actual events.

The problem was that while the state groups cache was limited in the
number of groups it could hold, each individual group could consist of
thousands of events.

Add published room list edit API

Remove some unused parameters from persist_event

Yield on EDU handling

Dedupe requested event list in _get_events

Update aliases event after deletion

Make registration idempotent, part 2

Remove dead code left over from presence changes

Attempt to update the appropriate `m.room.aliases` event after deleting
an alias. This may fail due to the deleter not being in the room.

Will also check if the canonical alias of the event is set to the
deleted alias, and if so will attempt to delete it.

Make registration idempotent