feat(mobile): iOS background sync (#1758)

* first run of getting background sync working in iOS

* got background sync calling into flutter

* added background task

* added necessary sync files

* fixed some names and added more implementations

* got as far as Hive.initFlutter

* brute force got to await Hive.initFlutter

* lots of print statements to figure out where execution is failing, and its failing at the root asset bundle in the localization.dart service

* first time working, got plugins registered

* removed broken cleanup code

* refactored

* linters

* now can pass user settings

* background service plugin uses app background processing instead of fetch

* renamed backgroundFetch to backgroundProcessing to make it clearer

* don't use max delay

* adds fetch back in

* fixes require charging default values and backup controller page

* fixes background fetch

* fixes ios not importing photos

* guarded path provider ios

* lint

* adds max tries for heartbeat to work in iOS

* fail after seconds

* timeout instead of fail after seconds

* removes release lock from system stop

* restores checkLockReleasedWithHeartbeat to Future<void>

* removes max tries from acquire lock

* fixes lock timeout with iOS

* restored for loop

* adds comments, made the AppRefresh task only run while not requiring network or charge

* fixed compile issue

* now both are registered and added better comments. also added ability for task to cancel itself

* added the podfile and pubspec

* added backup diagnostics to IOS and removed iOS ignored backup options and fixed network connectivity always required

* Added Alex's dev team

* styled debug list item, fixed refresh task not set bug, fixed enable / disable background service on platform channel

---------

Co-authored-by: Marty Fuhry <marty@fuhry.farm>
Co-authored-by: Alex Tran <alex.tran1502@gmail.com>

mobile/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme

@@ -43,11 +43,13 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      disableMainThreadChecker = "YES"
       launchStyle = "0"
       useCustomWorkingDirectory = "NO"
       ignoresPersistentStateOnLaunch = "NO"
       debugDocumentVersioning = "YES"
       debugServiceExtension = "internal"
+      enableGPUValidationMode = "1"
       allowLocationSimulation = "YES">
       <BuildableProductRunnable
          runnableDebuggingMode = "0">