Move user related model into models/user (#17781)

* Move user related model into models/user

* Fix lint for windows

* Fix windows lint

* Fix windows lint

* Move some tests in models

* Merge

models/user/error.go

@@ -0,0 +1,80 @@
+// 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 user
+
+import (
+	"fmt"
+)
+
+//  ____ ___
+// |    |   \______ ___________
+// |    |   /  ___// __ \_  __ \
+// |    |  /\___ \\  ___/|  | \/
+// |______//____  >\___  >__|
+//              \/     \/
+
+// ErrUserAlreadyExist represents a "user already exists" error.
+type ErrUserAlreadyExist struct {
+	Name string
+}
+
+// IsErrUserAlreadyExist checks if an error is a ErrUserAlreadyExists.
+func IsErrUserAlreadyExist(err error) bool {
+	_, ok := err.(ErrUserAlreadyExist)
+	return ok
+}
+
+func (err ErrUserAlreadyExist) Error() string {
+	return fmt.Sprintf("user already exists [name: %s]", err.Name)
+}
+
+// ErrUserNotExist represents a "UserNotExist" kind of error.
+type ErrUserNotExist struct {
+	UID   int64
+	Name  string
+	KeyID int64
+}
+
+// IsErrUserNotExist checks if an error is a ErrUserNotExist.
+func IsErrUserNotExist(err error) bool {
+	_, ok := err.(ErrUserNotExist)
+	return ok
+}
+
+func (err ErrUserNotExist) Error() string {
+	return fmt.Sprintf("user does not exist [uid: %d, name: %s, keyid: %d]", err.UID, err.Name, err.KeyID)
+}
+
+// ErrUserProhibitLogin represents a "ErrUserProhibitLogin" kind of error.
+type ErrUserProhibitLogin struct {
+	UID  int64
+	Name string
+}
+
+// IsErrUserProhibitLogin checks if an error is a ErrUserProhibitLogin
+func IsErrUserProhibitLogin(err error) bool {
+	_, ok := err.(ErrUserProhibitLogin)
+	return ok
+}
+
+func (err ErrUserProhibitLogin) Error() string {
+	return fmt.Sprintf("user is not allowed login [uid: %d, name: %s]", err.UID, err.Name)
+}
+
+// ErrUserInactive represents a "ErrUserInactive" kind of error.
+type ErrUserInactive struct {
+	UID  int64
+	Name string
+}
+
+// IsErrUserInactive checks if an error is a ErrUserInactive
+func IsErrUserInactive(err error) bool {
+	_, ok := err.(ErrUserInactive)
+	return ok
+}
+
+func (err ErrUserInactive) Error() string {
+	return fmt.Sprintf("user is inactive [uid: %d, name: %s]", err.UID, err.Name)
+}