Separate refdata categories into "internal" and "user" lists

Certain Ref Data categories and values (aka pick list values) need to exist in order for functionality in the system to work as designed.

To ensure that users can edit categories correctly and not remove required values, the ref data lists should be split into two types:

• internal (it is not possible to edit or delete an internal pick list/refdata category)
• user (it is not possible to edit a user pick list, but it is possible to delete it if it has no values attached)

• Internal categories only allow the editing of labels of existing values in the category (aka "pick list values")
• User categories can be freely edited by the user (adding or deleting values to the category as well as modifying the labels on existing values)

Specifically in Agreements:

And in Licenses:

In license settings, all "term value" lists created in the UI should be "User" lists. This also applies to the term lists we create in our default installations/test systems:

See screenshots for information about what it should/shouldn't be possible to do to Internal/User lists and values