Have 'while-no-input-ignore-events' handle idle timers too (Bug#49997)

Have 'while-no-input-ignore-events' handle idle timers too (Bug#49997)

* src/keyboard.c (read_char): Use Vwhile_no_input_ignore_events to
check which idle timers should be resumed (Bug#49997).
(init_while_no_input_ignore_events): New function to
initialize Vwhile_no_input_ignore_events.
(Vwhile_no_input_ignore_events): Say in doc-string that events in
this list do not stop idle timers.
* lisp/subr.el (while-no-input): Remove initialization of
'while-no-input-ignore-events'; do that in keyboard.c now.