feat(core): APP use new SDK component

[fangyinc]

Description

1. Use SDK ChatPromptTemplate in dbgpt/app/scene and base_chat
2. Format dbgpt/app codes.
3. Move the http APIs of conversation to dbgpt/serve/conversation
4. Use StorageConversation in base_chat

How Has This Been Tested?

make test

Snapshots:

Include snapshots for easier review.

Checklist:

• My code follows the style guidelines of this project
• I have already rebased the commits and make the commit message conform to the project standard.
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• Any dependent changes have been merged and published in downstream modules

Closes #1045

[csunny]

ChatExcel scene， when refreshed, the error will occur.

IsADirectoryError: [Errno 21] Is a directory: 'xxx/github/eosphoros-ai/DB-GPT/pilot/data/chat_excel/

[fangyinc]

More format

[csunny]

r+

[Aries-ckt]

r+