add supprot for OpenAI-API-Compatible llm (#1787)

### What problem does this PR solve?

#1771  add supprot for OpenAI-API-Compatible 

### Type of change

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

---------

Co-authored-by: Zhedong Cen <cenzhedong2@126.com>

web/src/interfaces/request/llm.ts

@@ -3,6 +3,7 @@ export interface IAddLlmRequestBody {
   llm_name: string;
   model_type: string;
   api_base?: string; // chat|embedding|speech2text|image2text
+  api_key: string;
 }
 
 export interface IDeleteLlmRequestBody {