Add prestate validation checks to state test loader

[gumb0]

Idea originated in #961 (review)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.51%. Comparing base (d62977d) to head (adc15ef).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1134      +/-   ##
==========================================
+ Coverage   94.50%   94.51%   +0.01%     
==========================================
  Files         167      167              
  Lines       18202    18240      +38     
==========================================
+ Hits        17201    17239      +38     
  Misses       1001     1001              

Flag	Coverage Δ
eof_execution_spec_tests	15.34% <19.56%> (+<0.01%)	⬆️
ethereum_tests	28.29% <17.39%> (-0.03%)	⬇️
ethereum_tests_silkpre	20.82% <15.78%> (-0.01%)	⬇️
execution_spec_tests	21.09% <19.56%> (-0.01%)	⬇️
unittests	89.78% <100.00%> (+0.02%)	⬆️

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Files with missing lines	Coverage Δ
test/statetest/statetest_loader.cpp	98.01% <100.00%> (+0.07%)	⬆️
test/unittests/state_transition_create_test.cpp	100.00% <100.00%> (ø)
test/unittests/statetest_loader_test.cpp	100.00% <100.00%> (ø)