User: use update function for password updates (#86419)

* Update password through Update function instead

* Remove duplicated to lower

* Refactor password code

pkg/services/user/error.go

@@ -22,4 +22,5 @@ var (
 	ErrEmptyUsernameAndEmail = errutil.BadRequest(
 		"user.empty-username-and-email", errutil.WithPublicMessage("Need to specify either username or email"),
 	)
+	ErrPasswordMissmatch = errutil.BadRequest("user.password-missmatch", errutil.WithPublicMessage("Invalid old password"))
 )