Add JS method for revokation of access to camera and microphone

It would be nice to have such a method (outside of std) to enable this function in a Safari extension bar.
https://github.com/EricssonResearch/openwebrtc-browser-extensions/pull/4 introduces accept/reject buttons, but once accepted a "revoke" button could be added if there was a JS method to revoke access.

Review the issue and the linked openwebrtc-browser-extensions pull request to understand how camera and microphone access is accepted or rejected in the Safari extension bar. Trace the existing permission flow and identify the JavaScript-facing entry point for a revoke operation. Done means an exposed method can revoke previously accepted camera and microphone access for the extension.

Written by the indexing model from the issue text.