[REQUEST] added setting for lightrag retrieval

### Reference Issues

_No response_

### Summary

lightrag has 4 mode of retrieval: naive, local, global and hybrid, it should be easily change from search settings

### Basic Example

lightrag has 4 mode of retrieval: naive, local, global and hybrid, it should be easily change from search settings

### Drawbacks

none that I can think of

### Additional information

_No response_