Previously we had a ViewModel class which was responsible for little more than creating an ObservableScope. However, since this ObservableScope would be created implicitly upon view model construction, it became a tad bit harder for callers to remember to eventually end the scope (as you wouldn't just have to remember to end ObservableScopes, but also to destroy ViewModels). Requiring the scope to be specified explicitly by the caller also makes it possible for the caller to reuse the scope for other purposes, reducing the number of scopes mentally in flight that need tending to, and for all state holders (not just view models) to be handled uniformly by helper functions such as generateKeyed$.
* Refactor media devices to live outside React as Observables
This moves the media devices state out of React to further our transition to a MVVM architecture in which we can more easily model and store complex application state. I have created an AppViewModel to act as the overarching state holder for any future non-React state we end up creating, and the MediaDevices reside within this. We should move more application logic (including the CallViewModel itself) there in the future.
* Address review feedback
* Fixes from ios debugging session: (#3342)
- dont use preferred vs selected concept in controlled media. Its not needed since we dont use the id for actual browser media devices (the id's are not even actual browser media devices)
- add more logging
- add more conditions to not accidently set a deviceId that is not a browser deviceId but one provided via controlled.
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Co-authored-by: Timo <16718859+toger5@users.noreply.github.com>
