fix: improve error handling across the SDK

[oliverlaz]

Overview

Improves how unhandled promise rejections and unhandled observable errors are handled across the SDK.

We used to ignore promise rejections in the PeerConnection event handlers. This lead to situations where tools like Sentry were reporting too many incidents due to this. Now, the SDK gracefully handles these errors.

In the device management part, the .listDevices() method throws an error when the user rejects the prompted browser permissions. Now, instead of erroring, we return an empty list.