ui/ncurses: Allow text wrapping in select widgets

Several string translations used in select widgets are longer than the
maximum possible width of the widget. Rather than associating several
FIELDs with a select option, use a fold_text callback to pad out
substrings of the original string such that the ncurses O_WRAP option
properly wraps strings within the field.

Signed-off-by: Samuel Mendoza-Jonas <sam.mj@au1.ibm.com>