[ColossalQA] refactor server and webui & add new feature (#5138)

* refactor server and webui & add new feature

* add requirements

* modify readme and ui

applications/ColossalQA/colossalqa/data_loader/document_loader.py

@@ -126,3 +126,11 @@ class DocumentLoader:
             else:
                 # May ba a directory, we strictly follow the glob path and will not load files in subdirectories
                 pass
+    
+    def clear(self):
+        """
+        Clear loaded data.
+        """
+        self.data = {}
+        self.kwargs = {}
+        self.all_data = []