### What problem does this PR solve?

Add code_executor_manager. #4977.

### Type of change

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

### 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?

Add back beartype

### Type of change

- [x] Refactoring

### What problem does this PR solve?

#1594

### Type of change

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

### What problem does this PR solve?

#918 
### Type of change

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

* add front end code

* change licence

* rename web_server to API

* change name to web_server

* clean rust version project

* clean rust version project

* build python version rag-flow