tests: move test data to a common location

[lengau]

fixes #39

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[codecov[bot]]

Codecov Report

Merging #60 (c17f90e) into main (09032a8) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##             main      #60   +/-   ##
=======================================
  Coverage   88.07%   88.07%           
=======================================
  Files          13       13           
  Lines         629      629           
  Branches      125      125           
=======================================
  Hits          554      554           
  Misses         61       61           
  Partials       14       14