Ability to add attribute values in bulk

Currently the only way to add allowed values to an attribute is one by one in the web dialog box.

It would be useful if we could add values in bulk, for example a list of yards and their related Divisions and Regions

I don’t expect this to be a regular occurrence, so I don’t think there is a need for this to have a fancy UI but maybe make it available via the API or the Web Loader.