Reduces initial sync times from ~30s to ~1s on accounts with heavily
populated rooms.
The problem was that f.e. RoomMember it would try to calculate the
display name, which involved looping each RoomMember to get their
display name to check for disambiguation. We now cache display names
to user IDs so we don't need to loop every member when disambiguating.
BREAKING CHANGE.
Scope each "getAvatarUrl" to be instance methods on the entity it
relates to (Room and RoomMember respectively). By doing this, we
can actually pull out specific state such as the `m.room.avatar`
event more easily rather than keeping it in the global cesspit
of `MatrixClient`.
This was complicated by `getHttpUriForMxc` and `getIdenticonUri`
which were attached to the HTTP API to pull out the `baseUrl` when
crafting the URL. Pull out this dependency out and explicitly pass
it in when crafting the URL. This is trivial to get from
`MatrixClient.getHomeserverUrl()`.
Accessed via MatrixEvent.sender property. Deep copy the list of state events
from initial sync for old/current RoomState so updating the .sender property
doesn't affect both of them. Reverse the insertion of initial sync MatrixEvents
so state diverges to *earlier* points in time. Add a 'forwardLooking' property
to MatrixEvent to determine which out of 'content' and 'prev_content' entities
should take into account e.g. when determining display names. Finally, always
create new RoomMembers when they are updated in order to prevent corrupting
(read: sharing the same member object) the MatrixEvent.sender property of
existing events in the timeline.
