* Use new `VerificationRequest.getQRCodeBytes()`
* Use new `VerificationRequest.otherDeviceId`
* Remove references to `VerificationRequest.channel`
* Replace references to `VerificationRequest.{requesting,receiving}UserId`
Normally these are guarded by `request.initiatedByMe` so we can trivially
replace it with `request.otherUserId` or `client.getUserId()`. In one place we
actually need to apply some logic.
* increase test coverage
* Even more test coverage
* Even more test coverage
* Use `getShowSasCallbacks()` and `getShowQrCodeCallbacks()`
... instead of type-casting
* Update method names
These methods got renamed in the js-sdk PR
* Fix strict typing errors
* Basic test for IncomingSasDialog
* Basic test for VerificationPanel
* Replace references to IGeneratedSas and ISasEvent
* Some secret references to the callbacks types
* Update references to `QrCodeEvent`, `SasEvent` and `VerificationEvent`
