Enable group calls without video and audio track by configuration of MatrixClient (#3162)
* groupCall: add configuration param to allow no audio and no camera
* groupCall: enable datachannel to do no media group calls
* groupCall: changed call no media property as object property
* groupCall: fix existing unit tests
* groupCall: remove not needed flag
* groupCall: rename property to allow no media calls
* groupCall: mute unmute even without device
* groupCall: switch to promise callbacks
* groupCall: switch to try catch
* test: filter dummy code from coverage
* test: extend media mute tests
* groupCall: move permission check to device handler
* mediaHandler: add error in log statement