add api for descriptor to root domain, tidying things up

files/api/Components.py

@@ -272,6 +272,7 @@ class System:
             print(f"System initializing, name {self.name}")
         # system contains an array of component objects
         self.components = []
+        self.component_class_tree = component_class_tree
         # initialize system properties and metrics dicts
         self._properties: Dict[str, str] = {}
         self._metrics: Dict[str, str] = {}
@@ -385,6 +386,9 @@ class System:
     def check_system_timer(self):
         time_lapsed = time.time() - float(self.recent_check)
         return time_lapsed < 30.0
+    
+    def get_component_class_tree(self):
+        return self.component_class_tree
 
     ########################################################
     # static metrics redis data functions