Update iOS deployment target to 13.0, enhance Flutter integration, and improve tender submission flow

- Changed the iOS deployment target from 12.0 to 13.0 in Podfile and project settings.
- Updated AppDelegate to support implicit Flutter engine initialization.
- Modified Info.plist to include scene configuration for multiple scenes.
- Enhanced CompletionOfDocumentsRouteData to accept a tenderId parameter.
- Implemented tender submission functionality in TenderDetailViewModel and updated UI components to reflect loading states and success/error messages.
- Added new strings for submission success and error notifications.

ios/Runner/AppDelegate.swift

@@ -2,12 +2,15 @@ import Flutter
 import UIKit
 
 @main
-@objc class AppDelegate: FlutterAppDelegate {
+@objc class AppDelegate: FlutterAppDelegate, FlutterImplicitEngineDelegate {
   override func application(
     _ application: UIApplication,
     didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
   ) -> Bool {
-    GeneratedPluginRegistrant.register(with: self)
     return super.application(application, didFinishLaunchingWithOptions: launchOptions)
   }
+
+  func didInitializeImplicitFlutterEngine(_ engineBridge: FlutterImplicitEngineBridge) {
+    GeneratedPluginRegistrant.register(with: engineBridge.pluginRegistry)
+  }
 }