Major Description
In daily works, we will cooperate with other guys to manage a shared model, generally the model is private, but we can let other roles, especially OPERATION role, to have the privilege to manage the indexes on this model.
But Kylin lacks some manners to easily enable this feature, hence we propose a new property `kylin.index.enable-operator-design` to make it work. When it's true, OPERATIONs can CRUD the indexes, but modify the model.
Of course, in order to bring in this switch, we have to change the default checks for the related APIs.