Build: Fix potential case-insensitive import collision for github.com/Unknwon/com (#18915)

* update gopkg.in/macaron.v1

* update github.com/go-macaron/binding

* update github.com/go-macaron/session

* Substitute github.com/Unknwon/com with github.com/unknwon/com

* Clean up modules using `go mod tidy`

* Substitute github.com/Unknwon/bra with github.com/unknwon/bra

vendor/github.com/unknwon/com/url.go

@@ -0,0 +1,41 @@
+// Copyright 2013 com authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package com
+
+import (
+	"encoding/base64"
+	"net/url"
+)
+
+// url encode string, is + not %20
+func UrlEncode(str string) string {
+	return url.QueryEscape(str)
+}
+
+// url decode string
+func UrlDecode(str string) (string, error) {
+	return url.QueryUnescape(str)
+}
+
+// base64 encode
+func Base64Encode(str string) string {
+	return base64.StdEncoding.EncodeToString([]byte(str))
+}
+
+// base64 decode
+func Base64Decode(str string) (string, error) {
+	s, e := base64.StdEncoding.DecodeString(str)
+	return string(s), e
+}