Fix access log (#14475)

Fix #14121, #14478.

The `AccessLog` middleware has to be after `Contexter` or `APIContexter` so that we can get `LoginUserName` if possible.
And also there is a **BREAK** change that it removed internal API access log.

modules/middlewares/request.go

@@ -0,0 +1,20 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package middlewares
+
+import (
+	"net/http"
+	"strings"
+)
+
+// IsAPIPath returns true if the specified URL is an API path
+func IsAPIPath(req *http.Request) bool {
+	return strings.HasPrefix(req.URL.Path, "/api/")
+}
+
+// IsInternalPath returns true if the specified URL is an internal API path
+func IsInternalPath(req *http.Request) bool {
+	return strings.HasPrefix(req.URL.Path, "/api/internal/")
+}