feat(itam): Add category property to device software model

ref: #345 #346

app/itam/models/device.py

@@ -426,6 +426,18 @@ class DeviceSoftware(DeviceCommonFields, SaveHistory):
         )
 
 
+    @property
+    def category(self):
+
+        category = None
+
+        if self.software:
+
+            category = self.software.category.id
+
+        return category
+
+
     @property
     def parent_object(self):
         """ Fetch the parent object """