Use generator to generate exceptions from yaml

Signed-off-by: Asai Neko <sugar@sne.moe>

internal/exception/middleware_gen.go

@@ -0,0 +1,9 @@
+// Code generated by gen-exception; DO NOT EDIT.
+package exception
+
+const (
+	MiddlewareGinLogger = "901"
+	MiddlewareJwt = "902"
+	MiddlewarePermission = "903"
+	MiddlewareApiVersion = "904"
+)