feat(linux): Get the isolate implementation somewhat working

lib/src/service/background/isolate.dart

@@ -0,0 +1,53 @@
+import 'dart:convert';
+import 'dart:isolate';
+import 'dart:ui';
+import 'package:logging/logging.dart';
+import 'package:moxlib/moxlib.dart';
+import 'package:moxxy_native/src/service/background/base.dart';
+import 'package:moxxy_native/src/service/config.dart';
+import 'package:moxxy_native/src/service/datasender/types.dart';
+import 'package:uuid/uuid.dart';
+
+class IsolateBackgroundService extends BackgroundService {
+  IsolateBackgroundService(this._sendPort);
+  final SendPort _sendPort;
+  final ReceivePort receivePort = ReceivePort();
+
+  /// A logger.
+  final Logger _log = Logger('IsolateBackgroundService');
+
+  @override
+  Future<void> send(BackgroundEvent event, {String? id}) async {
+    final data = DataWrapper(
+      id ?? const Uuid().v4(),
+      event,
+    );
+
+    _sendPort.send(jsonEncode(data.toJson()));
+  }
+
+  @override
+  Future<void> init(
+    ServiceConfig config,
+  ) async {
+    // Ensure that the Dart executor is ready to use plugins
+    // NOTE: We're not allowed to use this here. Maybe reusing the RootIsolateToken
+    //       (See IsolateForegroundService) helps?
+    // WidgetsFlutterBinding.ensureInitialized();
+    DartPluginRegistrant.ensureInitialized();
+
+    // Register the channel for Foreground -> Service communication
+    receivePort.listen((data) async {
+      // TODO(Unknown): Maybe do something smarter like pigeon and use Lists instead of Maps
+      await config
+          .handleData(jsonDecode(data! as String) as Map<String, dynamic>);
+    });
+
+    // Start execution
+    _log.finest('Setup complete. Calling main entrypoint...');
+    await config.entrypoint(config.initialLocale);
+  }
+
+  @override
+  void setNotificationBody(String body) {}
+}