* Add InputDeviceListUpdate
* Unbreak unit tests
* Process inbound device list updates from federation
- Persist the keys in the keyserver and produce key changes
- Does not currently fetch keys from the remote server if the prev IDs are missing
* Linting
* Persist partition|offset|user_id in the keyserver
Required for a query API which will be used by the syncapi which
will be called when a `/sync` request comes in which will return
a list of user IDs of people who have changed their device keys
between two tokens.
* Add tests and fix maxOffset bug
* s/offset/log_offset/g because 'offset' is a reserved word in postgres