decode/ethertype: Event on unknown ethertype

[jlucovsky]

Continuation of #11632

Issue: 7129

Create a decode/engine event if unknown ethertypes are observed.

Link to ticket: https://redmine.openinfosecfoundation.org/issues/7129

Describe changes:

• Add an event created when unknown ethertypes are observed
• Update schema with event counter
• Add rule for event.

Updates

• Include the ethertype when ethernet information is logged.

Provide values to any of the below to override the defaults.

• To use an LibHTP, Suricata-Verify or Suricata-Update pull request,
  link to the pull request in the respective _BRANCH variable.
• Leave unused overrides blank or remove.

SV_REPO=
SV_BRANCH=OISF/suricata-verify#1954
SU_REPO=
SU_BRANCH=
LIBHTP_REPO=
LIBHTP_BRANCH=

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.57%. Comparing base (45eb7e4) to head (b73296c).
Report is 331 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #11850      +/-   ##
==========================================
- Coverage   82.60%   82.57%   -0.03%     
==========================================
  Files         912      912              
  Lines      249351   249361      +10     
==========================================
- Hits       205965   205903      -62     
- Misses      43386    43458      +72     

Flag	Coverage Δ
fuzzcorpus	60.46% <88.88%> (-0.14%)	⬇️
livemode	18.74% <88.88%> (+0.01%)	⬆️
pcap	44.07% <88.88%> (+0.01%)	⬆️
suricata-verify	62.01% <100.00%> (-0.03%)	⬇️
unittests	58.94% <66.66%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

[suricata-qa]

WARNING:

field	baseline	test	%
	SURI_TLPR1_stats_chk
.uptime	649	623	95.99%

Pipeline 22938

[catenacyber]

Thanks for the work

CI : ✅
Code : good
Commits segmentation : ok, not sure if commit "doc/threshold: Threshold keyword clarifications" belongs here
Commit messages : good
Git ID set : looks fine for me
CLA : you already contributed
Doc update : nice addition 👏 not sure we should list all the currently recognized ether types as it will grow outdated
Redmine ticket : ok, should it target 8 ?
Rustfmt : no rust
Tests : nice, thanks (why does not json log 0x integers :-p)
Dependencies added: none

[victorjulien]

see inline

[jlucovsky]

Continued in #12495