all updates that can happen from the server side, without the client to have to ask explicitly
naming convention for the stream update specific messages is to add the “Update” prefix, even if it already exists
The track changed in some way, send new information
This includes everything from changing to a new track, new radio title, etc
This is not used for regular track progress updates
NOTE: this may or may not be sent for the initial track after startup as the client may connect after the track started