Users: Enable case insensitive login by default (#66134)

* enable case insensitive by default

* fix missing case-insensitive query

* fix missing case insensitive query

* fix missing case insensitive query in temp_user

* skip integration testing in mysql

* skip integration testing in mysql

* use t.cleanup

* lowercase only once

* aligned to only using sql as that is what we do in other parts

---------

Co-authored-by: Eric Leijonmarck <eric.leijonmarck@gmail.com>

pkg/services/user/userimpl/store.go

@@ -88,8 +88,16 @@ func (ss *sqlStore) Insert(ctx context.Context, cmd *user.User) (int64, error) {
 }
 
 func (ss *sqlStore) Get(ctx context.Context, usr *user.User) (*user.User, error) {
+	ret := &user.User{}
 	err := ss.db.WithDbSession(ctx, func(sess *db.Session) error {
-		exists, err := sess.Where("email=? OR login=?", usr.Email, usr.Login).Get(usr)
+		where := "email=? OR login=?"
+		login := usr.Login
+		email := usr.Email
+		if ss.cfg.CaseInsensitiveLogin {
+			where = "LOWER(email)=LOWER(?) OR LOWER(login)=LOWER(?)"
+		}
+
+		exists, err := sess.Where(where, email, login).Get(ret)
 		if !exists {
 			return user.ErrUserNotFound
 		}
@@ -101,7 +109,8 @@ func (ss *sqlStore) Get(ctx context.Context, usr *user.User) (*user.User, error)
 	if err != nil {
 		return nil, err
 	}
-	return usr, nil
+
+	return ret, nil
 }
 
 func (ss *sqlStore) Delete(ctx context.Context, userID int64) error {