fix(ios): directory picker - add App Documents option for iOS

- iOS limitation: empty folders cannot be selected via document picker
- Added bottom sheet with App Documents Folder as recommended option
- Shows info message explaining iOS limitation
- Files accessible via iOS Files app

Version: 2.0.7-preview2+38

.gitignore

@@ -49,3 +49,4 @@ ios/Pods/
 ios/.symlinks/
 ios/Flutter/Flutter.framework/
 ios/Flutter/Flutter.podspec
+android/app/libs/gobackend-sources.jar