dispaly gecko version in about dialog

app/lib/features/about/domain/providers.dart

@@ -0,0 +1,15 @@
+import 'package:flutter_mozilla_components/flutter_mozilla_components.dart';
+import 'package:package_info_plus/package_info_plus.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+part 'providers.g.dart';
+
+@Riverpod(keepAlive: true)
+Future<PackageInfo> packageInfo(Ref ref) {
+  return PackageInfo.fromPlatform();
+}
+
+@Riverpod()
+Future<String> geckoVersion(Ref ref) {
+  return GeckoBrowserService().getGeckoVersion();
+}