refactor: refactor relay part (#957)

* refactor: refactor relay part

* refactor: refactor config part

relay/channel/interface.go

@@ -0,0 +1,15 @@
+package channel
+
+import (
+	"github.com/gin-gonic/gin"
+	"net/http"
+	"one-api/relay/channel/openai"
+)
+
+type Adaptor interface {
+	GetRequestURL() string
+	Auth(c *gin.Context) error
+	ConvertRequest(request *openai.GeneralOpenAIRequest) (any, error)
+	DoRequest(request *openai.GeneralOpenAIRequest) error
+	DoResponse(c *gin.Context, resp *http.Response) (*openai.ErrorWithStatusCode, *openai.Usage, error)
+}