[MM-36472] Fix inconsistencies in Roles columns (#18390)

* Fix inconsistencies in Roles columns

* Add new migrations

model/user.go

@@ -60,6 +60,7 @@ const (
 	UserPasswordMaxLength = 72
 	UserLocaleMaxLength   = 5
 	UserTimezoneMaxRunes  = 256
+	UserRolesMaxLength    = 256
 )
 
 //msgp:tuple User
@@ -261,7 +262,6 @@ func (u *User) DeepCopy() *User {
 // IsValid validates the user and returns an error if it isn't configured
 // correctly.
 func (u *User) IsValid() *AppError {
-
 	if !IsValidId(u.Id) {
 		return InvalidUserError("id", "")
 	}
@@ -332,6 +332,11 @@ func (u *User) IsValid() *AppError {
 		}
 	}
 
+	if len(u.Roles) > UserRolesMaxLength {
+		return NewAppError("User.IsValid", "model.user.is_valid.roles_limit.app_error",
+			map[string]interface{}{"Limit": UserRolesMaxLength}, "user_id="+u.Id, http.StatusBadRequest)
+	}
+
 	return nil
 }