Suricata

When doing the research for #5976 I failed to see that we also have a config stats option for the human-readable logs to output 0 counters.
Due to not seeing this before, we now have two different setting names for basically the same thing, but in different logs:
zero-valued-counters for EVE https://github.com/OISF/suricata/blob/master/suricata.yaml.in#L319 and
null-values for stats.log https://github.com/OISF/suricata/blob/master/suricata.yaml.in#L444C9-L444C20.

I think we should use the same terminology, and that I should change the recently added one to null-values, as this one has been around for longer.

Opened a ticket so this can be registered as a lesson learned (hopefully!).