Add MXIDMapping for pseudoID rooms (#3112)

Add `MXIDMapping` on membership events when
creating/joining rooms.

syncapi/storage/postgres/current_room_state_table.go

@@ -343,9 +343,9 @@ func (s *currentRoomStateStatements) UpsertRoomState(
 		event.RoomID(),
 		event.EventID(),
 		event.Type(),
-		event.SenderID(),
+		event.UserID.String(),
 		containsURL,
-		*event.StateKey(),
+		*event.StateKeyResolved,
 		headeredJSON,
 		membership,
 		addedAt,

syncapi/storage/postgres/invites_table.go

@@ -101,7 +101,7 @@ func (s *inviteEventsStatements) InsertInviteEvent(
 		ctx,
 		inviteEvent.RoomID(),
 		inviteEvent.EventID(),
-		*inviteEvent.StateKey(),
+		inviteEvent.UserID.String(),
 		headeredJSON,
 	).Scan(&streamPos)
 	return

syncapi/storage/postgres/memberships_table.go

@@ -109,7 +109,7 @@ func (s *membershipsStatements) UpsertMembership(
 	_, err = sqlutil.TxStmt(txn, s.upsertMembershipStmt).ExecContext(
 		ctx,
 		event.RoomID(),
-		*event.StateKey(),
+		event.StateKeyResolved,
 		membership,
 		event.EventID(),
 		streamPos,

syncapi/storage/postgres/output_room_events_table.go

@@ -407,7 +407,7 @@ func (s *outputRoomEventsStatements) InsertEvent(
 		event.EventID(),
 		headeredJSON,
 		event.Type(),
-		event.SenderID(),
+		event.UserID.String(),
 		containsURL,
 		pq.StringArray(addState),
 		pq.StringArray(removeState),