fix: consider only dimensions with size >1 for plane-coordinate

[FelixS90]

[x] I followed the How to structure your PR.
[ ] Based on Commit Parsing: In case a new major release will be created (because the body or footer begins with 'BREAKING CHANGE:'), I created a new Jupyter notebook with a matching version.
[ ] Based on Commit Parsing: In case a new minor/patch release will be created (because PR title begins with 'feat'/('fix' or 'perf')), I optionally created a new Jupyter notebook with a matching version.
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Re-write of #16 due to changes in infrastructure.

Fixes #10

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.25%. Comparing base (3b2ea06) to head (d29ce54).

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #28   +/-   ##
=======================================
  Coverage   97.25%   97.25%           
=======================================
  Files           1        1           
  Lines         364      364           
  Branches       93       93           
=======================================
  Hits          354      354           
  Misses          5        5           
  Partials        5        5           

Components	Coverage Δ
pylibczirw_python	97.25% <ø> (ø)
pylibczirw_c	∅ <ø> (∅)