Attempt to decode SCTPChunkData data when possible

[guedou]

This PR fixes #4901

[codecov]

Codecov Report

❌ Patch coverage is 87.50000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 80.64%. Comparing base (4317859) to head (6f87a68).
⚠️ Report is 32 commits behind head on master.

Files with missing lines	Patch %	Lines
scapy/layers/sctp.py	87.50%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4915      +/-   ##
==========================================
- Coverage   80.88%   80.64%   -0.25%     
==========================================
  Files         368      370       +2     
  Lines       90340    91733    +1393     
==========================================
+ Hits        73070    73975     +905     
- Misses      17270    17758     +488     

Files with missing lines	Coverage Δ
scapy/contrib/diameter.py	99.56% <ø> (-0.01%)	⬇️
scapy/layers/sctp.py	95.47% <87.50%> (-0.34%)	⬇️

... and 60 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.