GroupCallEventhandler Tests (#2654)
* GroupCallEventhandler Tests
Fixes https://github.com/vector-im/element-call/issues/545
* Fix long line
* Fix strict mode error
Co-authored-by: Robin <robin@robin.town>
* Fix typo
Co-authored-by: Robin <robin@robin.town>
Co-authored-by: Robin <robin@robin.town>
