Update clip_explorer.py

Replace QTreeWidget with QTreeView

Author: woshimajintao

annotation_tool/ui/common/clip_explorer.py

@@ -7,7 +7,7 @@
 
 # Import the shared controls
 from ui.common.project_controls import UnifiedProjectControls
-
+ 
 class CommonProjectTreePanel(QWidget):
     """
     A unified Left Panel for both Classification and Localization.