generalize unmatricize to arbitrary axes

[ogauthe]

This PR generalizes unmatricize to arbitrary axes type.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.90%. Comparing base (9341d1d) to head (daaaf9e).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #66      +/-   ##
==========================================
+ Coverage   94.48%   94.90%   +0.41%     
==========================================
  Files          14       14              
  Lines         453      451       -2     
==========================================
  Hits          428      428              
+ Misses         25       23       -2     

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docs	0.00% <0.00%> (ø)

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[mtfishman]

@ogauthe should I merge this? Have you checked that this change allows you to use more TensorAlgebra.jl functionality in FusionTensors?

[ogauthe]

this is ready to merge