gh-152325: Add curses.has_mouse() and curses.window.mouse_trafo() (GH-152484)

gh-152325: Add curses.has_mouse() and curses.window.mouse_trafo() (GH-152484)

has_mouse() reports whether the mouse driver was successfully initialized.

window.mouse_trafo(y, x, to_screen) converts a coordinate pair between
window-relative and screen-relative coordinates, returning the (y, x) pair or
None if it lies outside the window.  Together these complete the curses mouse
interface.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>