Add EAPOL-Key layer

[TheMadProphet]

Checklist:

• [x] If you are new to Scapy: I have checked CONTRIBUTING.md (esp. section submitting-pull-requests)
• [x] I squashed commits belonging together
• [x] I added unit tests or explained why they are not relevant
• [x] I executed the regression tests for Python2 and Python3 (using tox or, cd test && ./run_tests_py2, cd test && ./run_tests_py3)
• [x] If the PR is still not finished, please create a Draft Pull Request

Adds new layer for EAPOL-Key according to IEEE 802.11-2016 standard. Additionally, the layer provides helper function for guessing 4-way handshake key number.

TODO: add key number detection for group as well. Add group tests

[codecov[bot]]

Codecov Report

Merging #3639 (e621b36) into master (280d596) will increase coverage by 36.62%. The diff coverage is 94.73%.

:exclamation: Current head e621b36 differs from pull request most recent head f41660f. Consider uploading reports for the commit f41660f to get more accurate results

Additional details and impacted files

@@             Coverage Diff             @@
##           master    #3639       +/-   ##
===========================================
+ Coverage   49.55%   86.17%   +36.62%     
===========================================
  Files         338      287       -51     
  Lines       75909    65145    -10764     
===========================================
+ Hits        37613    56138    +18525     
+ Misses      38296     9007    -29289     

Files	Coverage Δ
scapy/layers/eap.py	93.12% <94.73%> (+24.78%)	:arrow_up:

... and 314 files with indirect coverage changes

[stryngs]

@TheMadProphet This is something of interest to me. Do you have plans to keep developing this or?

[TheMadProphet]

@TheMadProphet This is something of interest to me. Do you have plans to keep developing this or?

No plans as of now. If you want EAPOL handshake layer in your application, feel free to use the code available in this PR.