EOF - EIP-7834 - support metadata section (draft)

[pdobacz]

Just a draft of the spike work on https://eips.ethereum.org/EIPS/eip-7834, not intended to be merge.

Tested using ethereum/execution-spec-tests#1116

Bearing in mind that this is just to dip the toe in the water, any feedback/thoughts welcome, we can use this as notes to make the future proper implementation more informed.

[codecov]

Codecov Report

Attention: Patch coverage is 86.95652% with 3 lines in your changes missing coverage. Please review.

Project coverage is 93.83%. Comparing base (7e658c9) to head (d4122c7).
Report is 13 commits behind head on master.

Files with missing lines	Patch %	Lines
lib/evmone/eof.cpp	86.95%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1113      +/-   ##
==========================================
- Coverage   93.84%   93.83%   -0.02%     
==========================================
  Files         159      159              
  Lines       17330    17348      +18     
==========================================
+ Hits        16263    16278      +15     
- Misses       1067     1070       +3     

Flag	Coverage Δ
eof_execution_spec_tests	18.68% <86.95%> (+0.07%)	⬆️
ethereum_tests	26.90% <69.56%> (+0.05%)	⬆️
ethereum_tests_silkpre	18.91% <0.00%> (-0.02%)	⬇️
execution_spec_tests	20.03% <0.00%> (-0.03%)	⬇️
unittests	88.98% <86.95%> (-0.01%)	⬇️

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

Files with missing lines	Coverage Δ
lib/evmone/eof.hpp	100.00% <ø> (ø)
lib/evmone/eof.cpp	85.73% <86.95%> (-0.06%)	⬇️