Fix mouse clicks on links under 'global-display-line-numbers-mode'

Fix mouse clicks on links under 'global-display-line-numbers-mode'

* src/indent.c (line_number_display_width): No longer static.
* src/lisp.h (line_number_display_width): Add prototype.
* src/keyboard.c (save_line_number_display_width)
(line_number_mode_hscroll): New functions.
(make_lispy_event): Call 'save_line_number_display_width' and
'line_number_mode_hscroll' to avoid interpreting up-event as drag
event when redisplay scrolls the text horizontally between the
down- and up-event to account for the changed width of the
line-number display.  (Bug#66655)