feat: Add nv23-skeleton

[rjan90]

As in the title, introduces the nv23-skeleton.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.62%. Comparing base (ea72025) to head (01bcb9e).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2000      +/-   ##
==========================================
+ Coverage   75.60%   75.62%   +0.01%     
==========================================
  Files         157      157              
  Lines       15746    15750       +4     
==========================================
+ Hits        11905    11911       +6     
+ Misses       3841     3839       -2     

Files	Coverage Δ
fvm/src/gas/price_list.rs	78.30% <100.00%> (+0.33%)	⬆️
fvm/src/machine/default.rs	73.26% <100.00%> (+1.39%)	⬆️
shared/src/version/mod.rs	7.69% <ø> (ø)