Adds the limit option to `--fuzz=[limit]`. the limit expresses a number
of iterations that *each fuzz test* will perform at maximum before
exiting. The limit argument supports also 'K', 'M', and 'G' suffixeds
(e.g. '10K').
Does not imply `--web-ui` (like unlimited fuzzing does) and prints a
fuzzing report at the end.
Closes#22900 but does not implement the time based limit, as after
internal discussions we concluded to be problematic to both implement
and use correctly.