Deprecate RemoveTrack (old signature)

This also removes all internal usage of RemoveTrack, and changes
the replacement function to RemoveTrackOrError rather than RemoveTrackNew.

Bug: webrtc:9534
Change-Id: Idf7bb17495686de77c70428dcbfb12278328ce59
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/244094
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35624}

sdk/objc/api/peerconnection/RTCPeerConnection.mm

@@ -515,7 +515,7 @@ void PeerConnectionDelegateAdapter::OnRemoveTrack(
 }
 
 - (BOOL)removeTrack:(RTC_OBJC_TYPE(RTCRtpSender) *)sender {
-  bool result = _peerConnection->RemoveTrack(sender.nativeRtpSender);
+  bool result = _peerConnection->RemoveTrackOrError(sender.nativeRtpSender).ok();
   if (!result) {
     RTCLogError(@"Failed to remote track %@", sender);
   }