Add Zarr tests

[CodyCBakerPhD]

#47

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 66.33%. Comparing base (a00b580) to head (a932479).
Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #51      +/-   ##
==========================================
+ Coverage   65.08%   66.33%   +1.24%     
==========================================
  Files          12       12              
  Lines         484      496      +12     
==========================================
+ Hits          315      329      +14     
+ Misses        169      167       -2     

Flag	Coverage Δ
unittests	66.33% <ø> (+1.24%)	⬆️

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Files	Coverage Δ
.../dandi_s3_log_parser/_dandi_s3_log_file_reducer.py	81.91% <ø> (ø)

... and 1 file with indirect coverage changes