refactor and organize code

internal/net/gphttp/methods.go

@@ -0,0 +1,20 @@
+package gphttp
+
+import "net/http"
+
+func IsMethodValid(method string) bool {
+	switch method {
+	case http.MethodGet,
+		http.MethodHead,
+		http.MethodPost,
+		http.MethodPut,
+		http.MethodPatch,
+		http.MethodDelete,
+		http.MethodConnect,
+		http.MethodOptions,
+		http.MethodTrace:
+		return true
+	default:
+		return false
+	}
+}