RPN function select list should be sorted when editing CDEF and VDEF's

**Describe the bug**
CDEF and VDEF RPN Functions not Ordered Properly

**To Reproduce**
Steps to reproduce the behavior:
1. Go to edit a CDEF or a VDEF
2. Edit a VDEF item that is a function
3. Review the Select list is not sorted

**Expected behavior**
The function names should be sorted to make them easier to spot.