LP1953381 not-allowed pointer for inactive buttons

LP1953381 not-allowed pointer for inactive buttons

Adds a style to change the mouse pointer to the "no" symbol for disabled
buttons.

To test:
1. Apply patch.
2. Go to an item record in the staff catalog.
3. Mouse over the "Set Default View" button (disabled by default on the
   Item Table tab).
4. The pointer should change to the "no" symbol.

Signed-off-by: Terran McCanna <tmccanna@georgialibraries.org>
Signed-off-by: Jane Sandberg <js7389@princeton.edu>