Add curses.nofilter() #151744

The curses module wraps filter() but not its inverse nofilter().

filter() puts curses into single-line mode — it forces LINES to 1 at the next initscr()/newterm(). nofilter(), an ncurses extension, undoes that effect.

Without it, code (or a test) that calls curses.filter() has no way to restore normal screen sizing for a later initscr()/newterm() in the same process.

Propose wrapping nofilter() as curses.nofilter(), guarded by a configure check, alongside the existing curses.filter().

Linked PRs

• gh-151744: Add curses.nofilter() #151747