dispaly gecko version in about dialog

packages/flutter_mozilla_components/lib/src/domain/services/gecko_browser.dart

@@ -13,6 +13,10 @@ class GeckoBrowserService {
 
   GeckoBrowserService({GeckoBrowserApi? api}) : _api = api ?? _apiInstance;
 
+  Future<String> getGeckoVersion() {
+    return _api.getGeckoVersion();
+  }
+
   Future<void> initialize(LogLevel logLevel, ContentBlocking contentBlocking) {
     return _api.initialize(logLevel, contentBlocking);
   }

packages/flutter_mozilla_components/lib/src/pigeons/gecko.g.dart

@@ -3007,6 +3007,34 @@ class GeckoBrowserApi {
 
   final String pigeonVar_messageChannelSuffix;
 
+  Future<String> getGeckoVersion() async {
+    final String pigeonVar_channelName = 'dev.flutter.pigeon.flutter_mozilla_components.GeckoBrowserApi.getGeckoVersion$pigeonVar_messageChannelSuffix';
+    final BasicMessageChannel<Object?> pigeonVar_channel = BasicMessageChannel<Object?>(
+      pigeonVar_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: pigeonVar_binaryMessenger,
+    );
+    final Future<Object?> pigeonVar_sendFuture = pigeonVar_channel.send(null);
+    final List<Object?>? pigeonVar_replyList =
+        await pigeonVar_sendFuture as List<Object?>?;
+    if (pigeonVar_replyList == null) {
+      throw _createConnectionError(pigeonVar_channelName);
+    } else if (pigeonVar_replyList.length > 1) {
+      throw PlatformException(
+        code: pigeonVar_replyList[0]! as String,
+        message: pigeonVar_replyList[1] as String?,
+        details: pigeonVar_replyList[2],
+      );
+    } else if (pigeonVar_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (pigeonVar_replyList[0] as String?)!;
+    }
+  }
+
   Future<void> initialize(LogLevel logLevel, ContentBlocking contentBlocking) async {
     final String pigeonVar_channelName = 'dev.flutter.pigeon.flutter_mozilla_components.GeckoBrowserApi.initialize$pigeonVar_messageChannelSuffix';
     final BasicMessageChannel<Object?> pigeonVar_channel = BasicMessageChannel<Object?>(