Add the WACS_* constants to the curses module

[serhiy-storchaka]

The curses module exposes the ACS_* line-drawing codes, but not their WACS_* counterparts.

X/Open Curses defines both: ACS_* are chtype characters, limited to the terminal's 8-bit alternate character set, and WACS_* are the same characters as cchar_t values for the wide-character interfaces.

Now that curses has complexchar cells (gh-151757), the WACS_* constants can be exposed as complexchar objects, added to the module by initscr() and newterm() like the ACS_* codes.

win.border(curses.WACS_VLINE, curses.WACS_VLINE,
           curses.WACS_HLINE, curses.WACS_HLINE)

Linked PRs

• gh-155863: Add the WACS_* constants to the curses module #155870