Fix up indices for users_who_share_rooms

Add configuration parameter to allow redaction of content from push m…

Add configuration parameter to allow redaction of content from push messages for google/apple devices

Store URL cache preview downloads separately

This makes it easier to clear old media out at a later date

Fix thinko in initial public room user spam

Don't work out users who share room with appservice users

only add new filter when not existent prevoisly

Add API to quarantine media

Add shutdown room API

Split out user directory to a separate process

Include users who you share a room with in user directory