decode/vntag: Add decoder for 802.1Qbh

[jlucovsky]

This PR adds support for decoding VNTAG packets (https://www.ieee802.org/1/files/public/docs2009/new-pelissier-vntag-seminar-0508.pdf)

Describe changes:

• VNTAG decode logic and tests
• VNTAG events

suricata-verify-pr: 489
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[codecov]

Codecov Report

Merging #6081 (890ff2d) into master (d4554ec) will increase coverage by 0.00%.
The diff coverage is 84.78%.

@@           Coverage Diff           @@
##           master    #6081   +/-   ##
=======================================
  Coverage   77.00%   77.00%           
=======================================
  Files         612      613    +1     
  Lines      187684   187727   +43     
=======================================
+ Hits       144530   144566   +36     
- Misses      43154    43161    +7     

Flag	Coverage Δ
fuzzcorpus	53.05% <5.55%> (+0.02%)	⬆️
suricata-verify	50.22% <58.82%> (-0.03%)	⬇️
unittests	63.27% <84.44%> (+<0.01%)	⬆️

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

[jlucovsky]

Continued in #6083