state: Rename .erasable → .erase_if_empty

[chfast]

No description provided.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (9af0b26) 97.91% compared to head (56e4a8d) 97.91%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #787   +/-   ##
=======================================
  Coverage   97.91%   97.91%           
=======================================
  Files         110      110           
  Lines       10578    10578           
=======================================
  Hits        10357    10357           
  Misses        221      221           

Flag	Coverage Δ
blockchaintests	60.23% <ø> (ø)
statetests	62.12% <100.00%> (ø)
statetests-silkpre	25.97% <100.00%> (ø)
unittests	95.90% <100.00%> (ø)

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Files	Coverage Δ
test/state/account.hpp	100.00% <ø> (ø)
test/state/host.cpp	94.58% <100.00%> (ø)
test/state/state.cpp	100.00% <100.00%> (ø)
test/state/state.hpp	100.00% <100.00%> (ø)