feat: implement new handlers for audio, image, embedding, and responses processing

- Added new handlers: AudioHelper, ImageHelper, EmbeddingHelper, and ResponsesHelper to manage respective requests.
- Updated ModelMappedHelper to accept request parameters for better model mapping.
- Enhanced error handling and validation across new handlers to ensure robust request processing.
- Introduced support for new relay formats in relay_info and updated relevant functions accordingly.

relay/relay-text.go

@@ -108,13 +108,11 @@ func TextHelper(c *gin.Context) (openaiErr *dto.OpenAIErrorWithStatusCode) {
 		}
 	}
 
-	err = helper.ModelMappedHelper(c, relayInfo)
+	err = helper.ModelMappedHelper(c, relayInfo, textRequest)
 	if err != nil {
 		return service.OpenAIErrorWrapperLocal(err, "model_mapped_error", http.StatusInternalServerError)
 	}
 
-	textRequest.Model = relayInfo.UpstreamModelName
-
 	// 获取 promptTokens，如果上下文中已经存在，则直接使用
 	var promptTokens int
 	if value, exists := c.Get("prompt_tokens"); exists {