feat(iOS, Android): add AppUUID Lib for plugins

[IT-MikeS]

Adds support for generating and accessing a UUID for a specific installation of an app from the core library.

Note: This UUID does not persist across app installations, so if the app is uninstalled the UUID is lost.

Plugins can leverage this by using the AppUUID class in both iOS and Android:

Android Plugin:

// Get or Create And Get, the UUID
String uuid = AppUUID.getAppUUID(this.getActivity());

//Regenerate the UUID
AppUUID.regenerateAppUUID(this.getActivity());

iOS Plugin:

// Get or Create And Get, the UUID
let uuid = AppUUID.getAppUUID()

//Regenerate the UUID
AppUUID.regenerateAppUUID();