iOS Swift Conversion (#2527)

Converts iOS implementation from Objective-c to Swift

# During the conversion process some updates to the code structure were also made
- Modularize codebase from single file to smaller focused files
- Untangled large nested IF statements
- Added more null checks, since Swift is more strict with null pointers
- Added property to allow for decoding of local video sources with self contained key for offline playback
- Updates example apps to test react-native 0.63.4 and uses auto native dependency imports for android and ios

examples/basic/windows/VideoPlayer/App.h

@@ -1,15 +1,18 @@
-#pragma once
-
-#include "App.xaml.g.h"
-
-
-
-namespace winrt::VideoPlayer::implementation
-{
-    struct App : AppT<App>
-    {
-        App() noexcept;
-    };
-} // namespace winrt::VideoPlayer::implementation
-
-
+#pragma once
+
+#include "App.xaml.g.h"
+
+namespace activation = winrt::Windows::ApplicationModel::Activation;
+
+namespace winrt::videoplayer::implementation
+{
+    struct App : AppT<App>
+    {
+        App() noexcept;
+        void OnLaunched(activation::LaunchActivatedEventArgs const&);
+        void OnSuspending(IInspectable const&, Windows::ApplicationModel::SuspendingEventArgs const&);
+        void OnNavigationFailed(IInspectable const&, Windows::UI::Xaml::Navigation::NavigationFailedEventArgs const&);
+      private:
+        using super = AppT<App>;
+    };
+} // namespace winrt::videoplayer::implementation