Added option to open FileViewer always with system dialog, enabled by default on iOS

lib/storage/fileView/fileViewSettings.dart

@@ -0,0 +1,13 @@
+import 'package:json_annotation/json_annotation.dart';
+
+part 'fileViewSettings.g.dart';
+
+@JsonSerializable()
+class FileViewSettings {
+  bool alwaysOpenExternally;
+
+  FileViewSettings({required this.alwaysOpenExternally});
+
+  factory FileViewSettings.fromJson(Map<String, dynamic> json) => _$FileViewSettingsFromJson(json);
+  Map<String, dynamic> toJson() => _$FileViewSettingsToJson(this);
+}