Suricata

If we look at https://app.codecov.io/gh/OISF/suricata/blob/master/src/detect-ttl.c
we will notice that there is no code coverage for ttl as a prefilter.

This ticket's work includes:
- Identify other ttl keywords or usage that may also need coverage
- Add suricata-verify tests with rules that make use of those
- Check if we need to update our userguide documentation on those keywords, and improve it accordingly