Feat: Add config parameter to allow only certain units to be displayed for tokenization based on unit status

[ccornick]

There should be an optional config parameter added to Climate Portal such that a user can define which unit statuses should be filtered out when tokenizing.

The idea here is that a registry should NEVER tokenize a retired unit, so why would we even show retired units on the Climate-Portal-UI?

I think the best way to do achieve this is to have a config parameter which defines which unit statuses should be allowed for tokenization. If none entered, then default to show all units.