Fix vector show

[mtfishman]

Along with ITensor/SparseArraysBase.jl#45 and ITensor/SparseArraysBase.jl#46, this fixes #77.

To-do:

• Add tests.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.24%. Comparing base (10f6ebf) to head (5b32818).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #79      +/-   ##
==========================================
+ Coverage   76.22%   76.24%   +0.02%     
==========================================
  Files          28       28              
  Lines        1081     1082       +1     
==========================================
+ Hits          824      825       +1     
  Misses        257      257              

Flag	Coverage Δ
docs	16.24% <0.00%> (-0.02%)	⬇️

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[mtfishman]

This now relies on #46 for tests to pass.