New functions '(set-)window-cursor-type'

New functions '(set-)window-cursor-type'

* src/window.h (struct window): Add 'cursor_type' slot.
(wset_cursor_type): New inline function.
* src/xdisp.c (get_window_cursor_type): Consult 'cursor_type'.
* src/window.c (make_window): Initialize 'cursor_type' to t.
(Fset_window_cursor_type, Fwindow_cursor_type): New functions.
(syms_of_window): List their symbols.
* doc/lispref/windows.texi (Window Point): Document them.
* doc/lispref/frames.texi (Cursor Parameters): Mention
new 'set-window-cursor-type'.
* etc/NEWS: Announce new functions.  (Bug#70622)