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/scene/model/scene_details_model.dart

@@ -90,11 +90,11 @@ class Action {
   static Action? fromJson(Map<String, dynamic> json) {
     if (json['name'] != null && json['type'] != null) {
       return Action(
-        actionExecutor: json["actionExecutor"],
-        entityId: json["entityId"],
-        name: json['name'],
-        type: json['type'],
-        productType: json['productType'],
+        actionExecutor: json["actionExecutor"] ?? '',
+        entityId: json["entityId"] ?? '',
+        name: json['name'] as String?,
+        type: json['type'] as String?,
+        productType: json['productType'] as String?,
       );
     }
     if (json["executorProperty"] == null) {
@@ -102,10 +102,10 @@ class Action {
     }
 
     return Action(
-      actionExecutor: json["actionExecutor"],
-      entityId: json["entityId"],
+      actionExecutor: json["actionExecutor"] ?? '',
+      entityId: json["entityId"] ?? '',
       executorProperty: ExecutorProperty.fromJson(json["executorProperty"]),
-      productType: json['productType'],
+      productType: json['productType'] as String?,
     );
   }