Transition to callkit_incoming API

[Ayman-Barghout]

Update the package with iOS implementation and update the Android implementation based on flutter_callkit_incoming package, but with a minimalist approach and more data typing.

UI on Android:

Full-screen audio:

Full-screen video:

Notification:

[linear[bot]]

D-1356 Update `flutter_callkeep` API using `flutter_callkit_incoming`

Update our package's API based on the API in `flutter_callkit_incoming` and improve its API/Documentation.

[acanturgut]

For future, i personally dont like this screen. i re worked this screen before. better to rework on it next year. I think we can do it great incoming call screen which fit out desing.