Move "user media" logic into its own provider.

- This new provider is meant to be reused by the settings in the future

Change-Id: I513c07f2390445fb4802091b316244665218f948
diff --git a/client/src/components/VideoOverlay.tsx b/client/src/components/VideoOverlay.tsx
index 195f5f9..9307f9b 100644
--- a/client/src/components/VideoOverlay.tsx
+++ b/client/src/components/VideoOverlay.tsx
@@ -21,6 +21,7 @@
 import { useNavigate } from 'react-router-dom';
 
 import { useCallContext } from '../contexts/CallProvider';
+import { useUserMediaContext } from '../contexts/UserMediaProvider';
 import { VideoElementWithSinkId } from '../utils/utils';
 import VideoStream, { VideoStreamProps } from './VideoStream';
 
@@ -79,7 +80,7 @@
     currentMediaDeviceIds: {
       audiooutput: { id: audioOutDeviceId },
     },
-  } = useCallContext();
+  } = useUserMediaContext();
   const navigate = useNavigate();
 
   // TODO: For now, `remoteStream` is the first remote stream in the array.