Refactor device filtering logic and improve code readability

- Extracted the logic for filtering implemented devices into a separate method `_getOnlyImplementedDevices`
- Created a set `allowedDevices` to store the allowed device types
- Updated the filtering logic to use the `allowedDevices` set for checking device types
- Removed unnecessary conditions for filtering devices

Fix nullability issues in `Action` model

- Added null checks for `actionExecutor`, `entityId`, `name`, `type`, and `productType` properties in the `fromJson` method of the `Action` model
- Set default values for `actionExecutor` and `entityId` if they are null
- Updated the type casting for `name`, `type`, and `productType` properties to avoid potential nullability issues

lib/features/devices/bloc/device_manager_bloc/device_manager_bloc.dart

@@ -169,18 +169,26 @@ class DeviceManagerBloc extends Bloc<DeviceManagerEvent, DeviceManagerState> {
     }
   }
 
-  _getOnlyImplementedDevices(List<DeviceModel> devices) {
+  List<DeviceModel> _getOnlyImplementedDevices(List<DeviceModel> devices) {
     List<DeviceModel> implementedDevices = [];
-    for (int i = 0; i < devices.length; i++) {
-      if (devices[i].productType == DeviceType.AC ||
-          devices[i].productType == DeviceType.DoorLock ||
-          devices[i].productType == DeviceType.Gateway ||
-          devices[i].productType == DeviceType.WallSensor ||
-          devices[i].productType == DeviceType.CeilingSensor ||
-          devices[i].productType == DeviceType.ThreeGang ||
-          devices[i].productType == DeviceType.OneGang) {
-        implementedDevices.add(devices[i]);
+
+    const allowedDevices = <DeviceType>{
+      DeviceType.OneGang,
+      DeviceType.TwoGang,
+      DeviceType.ThreeGang,
+      DeviceType.AC,
+      DeviceType.DoorLock,
+      DeviceType.Gateway,
+      DeviceType.WallSensor,
+      DeviceType.CeilingSensor
+    };
+
+    for (final device in devices) {
+      final isDeviceAllowed = allowedDevices.contains(device.productType);
+      if (isDeviceAllowed) {
+        implementedDevices.add(device);
       }
+      return implementedDevices;
     }
     return implementedDevices;
   }