add econtrol gasstation view and logic

lib/controller/home_controller.dart

@@ -1,3 +1,4 @@
+import 'package:flutter_tank_web_app/pages/gasstations_view.dart';
 import 'package:get/get.dart';
 
 import '../models/tank_model.dart';
@@ -105,4 +106,8 @@ class HomeController extends GetxController {
   void goToGraphPage() {
     Get.toNamed(GraphPage.namedRoute, arguments: listTankModel);
   }
+
+  void goToGasStations() {
+    Get.toNamed(GasstationsPage.namedRoute);
+  }
 }