ios: Picture-in-picture while in calls (#3792)

* ios: Picture-in-picture while in calls

* simplify

* improvements

* back button and lots of small issues

* layout

* padding

* back button

* animation, padding, fullscreen

* end active call button

* removed unused code

* unused line

* transition

* better

* better

* deinit PiP controller

* stop camera after call end

* formatting

* stop capture if active

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Co-authored-by: Avently <avently@local>
Co-authored-by: Evgeny Poberezkin <evgeny@poberezkin.com>

apps/ios/Shared/Model/ChatModel.swift

@@ -90,6 +90,7 @@ final class ChatModel: ObservableObject {
     @Published var activeCall: Call?
     let callCommand: WebRTCCommandProcessor = WebRTCCommandProcessor()
     @Published var showCallView = false
+    @Published var activeCallViewIsCollapsed = false
     // remote desktop
     @Published var remoteCtrlSession: RemoteCtrlSession?
     // currently showing invitation