Show the whole transport in debug UI and logs

A transport may soon carry a LiveKit SFU `url` instead of, or as well as,
a `livekit_service_url`, so a service URL alone no longer identifies it.
Pass the whole transport to the tiles' debug stats and print it as JSON in
log lines instead of picking out the service URL.

src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts

@@ -143,9 +143,9 @@ export function createRemoteMatrixLivekitMembers$({
           // Log whether the member could be matched to a LiveKit participant,
           // since a tile shows "waiting for media" for as long as it cannot.
           participant$.pipe(scope.bind()).subscribe((p) => {
-            const url = data$.value.connection?.transport.livekit_service_url;
+            const transport = data$.value.connection?.transport;
             logger.info(
-              `[RemoteMatrixLivekitMembers] ${rtcBackendIdentity}: LiveKit participant ${p ? `matched (${p.sid})` : "missing"} on ${url ?? "no connection"}`,
+              `[RemoteMatrixLivekitMembers] ${rtcBackendIdentity}: LiveKit participant ${p ? `matched (${p.sid})` : "missing"} on ${transport ? JSON.stringify(transport) : "no connection"}`,
             );
           });
           // will only get called once per backend identity.