### What problem does this PR solve?


### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

#980 

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

- Added support for Baichuan LLM

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

Co-authored-by: 海贼宅 <stu_xyx@163.com>

### What problem does this PR solve?

#922 
### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?
Bug fixes for the VolcEngine

- Bug fix for front-end configuration code of VolcEngine

- Bug fix for tokens counting logic of VolcEngine


### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

---------

Co-authored-by: 海贼宅 <stu_xyx@163.com>

### What problem does this PR solve?

#882 

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

- The main idea is to assemble **ak**, **sk**, and **ep_id** into a
dictionary and store it in the database **api_key** field
- I don’t know much about the front-end, so I learned from Ollama, which
may be redundant.

### Configuration method

- model name

- Format requirements: {"VolcEngine model name":"endpoint_id"}
    - For example: {"Skylark-pro-32K":"ep-xxxxxxxxx"}
    
- Volcano ACCESS_KEY
- Format requirements: VOLC_ACCESSKEY of the volcano engine
corresponding to the model

- Volcano SECRET_KEY
- Format requirements: VOLC_SECRETKEY of the volcano engine
corresponding to the model
    
### What problem does this PR solve?

_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?


### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?


### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

#834 

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?


### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

#709

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

#709 
### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

#666 

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?
#614 

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

#477 

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?


Issue link:#345

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Issue link:#299

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Issue link:#264
### Type of change


- [x] Documentation Update
- [x] Refactoring

### What problem does this PR solve?

Issue link:#265

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Issue link:#265

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Issue link:#221

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._

Issue link:#[[Link the issue
here](https://github.com/infiniflow/ragflow/issues/226)]

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

* add front end code

* change licence

* clean rust version project

* clean rust version project

* build python version rag-flow

* add llm API

* refine llm API

* format code

* use minio to store uploaded files; build dialog server;