More invite support (#979)

* Update gomatixserverlib

* Try to build invite stripped state if not given to us

* SendInvite improvements

* Transpose invite_room_state into invite_state.events for sync API

* Remove syncapi debugging output

* Use RespInviteV2

* Update gomatrixserverlib

* Send the invite event as a normal roomserver event too, for incorporating into room (should this be done by the roomserver automatically for invite inputs?)

* Federation sender use invite_room_state, room server try to insert membership state

* Check supported room versions on the invite endpoint

* Prevent roomserver query API from trying to handle requests for stub rooms

* Adding a nolint

* Replace IsRoomStub with RoomNIDExcludingStubs, fix query API to use that instead

* Review comments

roomserver/input/membership.go

@@ -144,7 +144,7 @@ func updateToInviteMembership(
 		// consider a single stream of events when determining whether a user
 		// is invited, rather than having to combine multiple streams themselves.
 		onie := api.OutputNewInviteEvent{
-			Event:       (*add).Headered(roomVersion),
+			Event:       add.Headered(roomVersion),
 			RoomVersion: roomVersion,
 		}
 		updates = append(updates, api.OutputEvent{