fix(llm): update config in time after apply changes in UI

[returnToInnocence]

Brief description

1. Fixed an issue where rag web demo could not update system configuration in time after configuration file changes in file hugegraph-llm/src/hugegraph_llm/demo/rag_demo/app.py
   • graph config, the picture is as follows
     
   • prompt, the picture is as follows
     
   • rag with hugegraph, as follows
     

To avoid errors that result in an empty return value in file hugegraph-llm/src/hugegraph_llm/demo/rag_demo/configs_block.py

2. Adjust the order of functions and classes in file hugegraph-llm/src/hugegraph_llm/config/config.py

3. Adjust the format of the prompt to make it easier to read in file hugegraph-llm/src/hugegraph_llm/config/config_data.py

4. Add the ability to save prompt to the configuration file after a button click to the kg build section in file hugegraph-llm/src/hugegraph_llm/demo/rag_demo/vector_graph_block.py, the position as follows
   

issue

fix some of the #91