main/ncurses: fix libcurses.a symlink in -static subpackage

While at it, also provide symlinks from lib{lib}.a to lib{lib}w.a analog to what we do already for the shared library.

This changes the libcurses.a symlink to: libcurses.a → libncurses.a → libncursesw.a

Fixes #13391 (closed)