Add delete task functionality (#72)

closes #62

Reviewed-on: #72

frontend/allowance-planner-v2/src/app/pages/edit-task/edit-task.page.ts

@@ -72,4 +72,9 @@ export class EditTaskPage implements OnInit {
 
     this.router.navigate(['/tabs/tasks']);
   }
+
+  deleteTask() {
+    this.taskService.deleteTask(this.id);
+    this.router.navigate(['/tabs/tasks']);
+  }
 }