Decouple unit test, remove intermediate unittestbridge package (#17662)

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

models/unittest/reflection.go

@@ -0,0 +1,41 @@
+// Copyright 2021 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 unittest
+
+import (
+	"log"
+	"reflect"
+)
+
+func fieldByName(v reflect.Value, field string) reflect.Value {
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
+	f := v.FieldByName(field)
+	if !f.IsValid() {
+		log.Panicf("can not read %s for %v", field, v)
+	}
+	return f
+}
+
+type reflectionValue struct {
+	v reflect.Value
+}
+
+func reflectionWrap(v interface{}) *reflectionValue {
+	return &reflectionValue{v: reflect.ValueOf(v)}
+}
+
+func (rv *reflectionValue) int(field string) int {
+	return int(fieldByName(rv.v, field).Int())
+}
+
+func (rv *reflectionValue) str(field string) string {
+	return fieldByName(rv.v, field).String()
+}
+
+func (rv *reflectionValue) bool(field string) bool {
+	return fieldByName(rv.v, field).Bool()
+}