Disambiguate between types of "member" (#2807)

We have Matrix room members and MatrixRTC session memberships. Livekit also has rooms.

So, this attempts to make it more obvious as to what type you are referring to.

src/state/CallViewModel.ts

@@ -306,7 +306,7 @@ class ScreenShare {
 
 type MediaItem = UserMedia | ScreenShare;
 
-function findMatrixMember(
+function findMatrixRoomMember(
   room: MatrixRoom,
   id: string,
 ): RoomMember | undefined {
@@ -428,7 +428,7 @@ export class CallViewModel extends ViewModel {
           function* (this: CallViewModel): Iterable<[string, MediaItem]> {
             for (const p of [localParticipant, ...remoteParticipants]) {
               const id = p === localParticipant ? "local" : p.identity;
-              const member = findMatrixMember(this.matrixRoom, id);
+              const member = findMatrixRoomMember(this.matrixRoom, id);
               if (member === undefined)
                 logger.warn(
                   `Ruh, roh! No matrix member found for SFU participant '${p.identity}': creating g-g-g-ghost!`,