LP1951996 Preferred names in group member details

LP1951996 Preferred names in group member details

Adds columns for preferred family, middle, and first names to group member
details.  These added columns are hidden by default.

To test:
1. In a patron's record add a preferred first, middle, and last name.
2. Go to Other - Group member details and notice that there are no columns
   for preferred.
3. Apply patch.
4. Go to group member details and use the drop-down to display the preferred
   columns.
5. Add some more patrons to the group for good measure.

Signed-off-by: Garry Collum <gcollum@gmail.com>