Client Improvement

1. [GUI] Reduce the response time when switching themes and fix issues where some widgets' themes are not consistent.
2. [GUI] Fix the issue that mainwindow would suddenly hide when interacting with certain message boxes.
3. [GUI] Support refreshing tables & adding local models in the model management interface.
4. [GUI] Add message box to pop up when update-check / download is failed.
5. [GUI] Widget library update (see details in 'QSimpleWidget' repo)

EVT_GUI/Functions.py

@@ -11,6 +11,20 @@
 
 ##############################################################################################################################
 
+def Function_FindChildUI(
+    ParentUI: QWidget,
+    ChildType: object
+):
+    '''
+    Function to find child UI
+    '''
+    ParentUI_Children = ParentUI.children()
+
+    for ParentUI_Child in ParentUI_Children:
+        if isinstance(ParentUI_Child, ChildType):
+            return ParentUI_Child
+
+
 def Function_FindParentUI(
     ChildUI: QWidget,
     ParentType: object