### What problem does this PR solve?

Enhance capability of `list_docs`.

Breaking change: change method from `GET` to `POST`.

### Type of change

- [x] Refactoring
- [x] Enhancement with breaking change

### What problem does this PR solve?

Enhance capability of `list_kbs`.

Breaking change: change method from `GET` to `POST`.

### Type of change

- [x] Refactoring
- [x] Enhancement with breaking change

### What problem does this PR solve?

Fixes #5923 

Fixes the readonly variables from payload at
 /datasets/<dataset_id> 

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

Now if user tries to modify readonly values then it will show " The
input parameters are invalid. "

invalid_keys = {"id", "embd_id", "chunk_num", "doc_num", "parser_id",
"create_date", "create_time", "created_by",
"status","token_num","update_date","update_time"}
    if any(key in req for key in invalid_keys):
return get_error_data_result(message="The input parameters are
invalid.")
i have include those readonly keys in invalid_keys

### Type of change

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

---------

Co-authored-by: Raghav <2020csb1115@iitrpr.ac.in>

### What problem does this PR solve?

Add license statement.

### Type of change

- [x] Refactoring

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

### What problem does this PR solve?

Fix errors detected by Ruff

### Type of change

- [x] Refactoring

### What problem does this PR solve?

1. Failed update dataset case
2. Upload and parse text file

### Type of change

- [x] Other (please describe): test cases

---------

Signed-off-by: jinhai <haijin.chn@gmail.com>

### What problem does this PR solve?

Test cases about dataset

### Type of change

- [x] Other (please describe): test cases

---------

Signed-off-by: jinhai <haijin.chn@gmail.com>

### What problem does this PR solve?

1. Read KB list path parameter, page_number and page_size, which type
isn't int
2. Add cases on create / list / delete datasets.

### Type of change

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

Signed-off-by: jinhai <haijin.chn@gmail.com>

### What problem does this PR solve?

Add tests for frontend API

### Type of change

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

---------

Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>

### What problem does this PR solve?

Add test for API

### Type of change

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

---------

Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>
Co-authored-by: Zhichang Yu <yuzhichang@gmail.com>

### What problem does this PR solve?

Test Cases

### Type of change

- [x] Refactoring

Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>

### What problem does this PR solve?

Refactor Dataset API

### Type of change

- [x] Refactoring

---------

Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>

### What problem does this PR solve?

SDK for Assistant
#1102 

### Type of change

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

Co-authored-by: Feiue <10215101452@stu.ecun.edu.cn>

### What problem does this PR solve?

Added the ability to create and update dataset for SDK

### Type of change


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

---------

Co-authored-by: root <root@xwg>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

### What problem does this PR solve?

You can use sdk to create a dataset

### Type of change

- [x] New Feature

---------

Co-authored-by: root <root@xwg>

### What problem does this PR solve?

Adds download_document api

### Type of change


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

### What problem does this PR solve?

Added get_dataset and update_dataset API.
Fixed delete_dataset.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] New Feature (non-breaking change which adds functionality)
- [x] Documentation Update

### What problem does this PR solve?

This PR have completed both HTTP API and Python SDK for 'list_dataset".
In addition, there are tests for it.

### Type of change

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

### What problem does this PR solve?

This PR have finished 'create dataset' of both HTTP API and Python SDK.
HTTP API:
```
curl --request POST --url http://<HOST_ADDRESS>/api/v1/dataset   --header 'Content-Type: application/json' --header 'Authorization: <ACCESS_KEY>' --data-binary '{
  "name": "<DATASET_NAME>"
}'
```

Python SDK:
```
from ragflow.ragflow import RAGFLow
ragflow = RAGFLow('<ACCESS_KEY>', 'http://127.0.0.1:9380')
ragflow.create_dataset("dataset1")

```

TODO: 
- ACCESS_KEY is the login_token when user login RAGFlow, currently.
RAGFlow should have the function that user can add/delete access_key.

### Type of change

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

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>