Add basic implementation of AUTOSAR SecOC

[polybassa]

This PR adds a very basic implementation of AUTOSAR SecOC packets.

Basic therefore, because the actual implementation of the message authentication code calculation is left to the user, since there is no standard across OEMs.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 78.82353% with 18 lines in your changes are missing coverage. Please review.

Project coverage is 80.27%. Comparing base (8461c2e) to head (88f144c). Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4395      +/-   ##
==========================================
- Coverage   81.56%   80.27%   -1.29%     
==========================================
  Files         352      353       +1     
  Lines       83897    84004     +107     
==========================================
- Hits        68431    67438     -993     
- Misses      15466    16566    +1100     

Files	Coverage Δ
scapy/contrib/automotive/autosar/pdu.py	100.00% <100.00%> (ø)
scapy/contrib/automotive/autosar/secoc.py	78.57% <78.57%> (ø)

... and 46 files with indirect coverage changes

[polybassa]

@gpotter2 Ready for review.