Is a unique index needed on ufgroup.name?

In trying to figure out how to make the CustomGroupData.xml import for CiviEngage work, it seems that the best approach is to use a unique name for entities that is not dependent on the id, as that makes the data import liable to fail depending on what has previously happened in the database. The unique name needs to be used later in the xml file for references back to the entity by children.

In the case of UFGroup, it seems that the name field should be able to play this role - the comment in the schema is that it is Name of the UF group for directly addressing it in the codebase. In order to ensure this is possible, we should add a unique index on this field, as per the attached patch.