### What problem does this PR solve?
https://github.com/infiniflow/ragflow/issues/9385
Based on my understanding, I think checking empty string is fine
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
---------
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>
### What problem does this PR solve?
#9082#6365
<u> **WARNING: it's not compatible with the older version of `Agent`
module, which means that `Agent` from older versions can not work
anymore.**</u>
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
```
Invoke agent
To be able to interact dynamically with the API, there is a customizable Data Type JSON or FormData, the default is JSON
```
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
---------
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>
### What problem does this PR solve?
Invoke component can be used to call third party services.
Tried GET/POST/PUT from web UI, and found PUT request failed like this:
(test api: api/v1/chats/<assistant_id>)
```
{"code":100,"data":null,"message":"AttributeError("'NoneType' object has
no attribute 'get'")"}
```
Root cause: Invoke PUT with a 'data=args' parameter, which is a form-encoded data, however the default content type setting of request header is application/json. The test api could not deal with such case.
Fix: use the 'json' parameter of reqeusts.put(), same as Invoke POST. Do not use the 'data' parameter.
Another way is to use 'data=json.dumps(args)'.
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
### What problem does this PR solve?
fix bug, agent invoke can not get params from begin
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
Co-authored-by: wangrui <wangrui@haima.me>
