expect closed linestring for polygon

[danielsparing]

resolves #457

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (f734d66) 93.85% compared to head (f9e3fa0) 93.84%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #501      +/-   ##
==========================================
- Coverage   93.85%   93.84%   -0.01%     
==========================================
  Files         239      239              
  Lines        6202     6209       +7     
  Branches      108      108              
==========================================
+ Hits         5821     5827       +6     
- Misses        381      382       +1     

Files	Coverage Δ
...osaic/core/geometry/polygon/MosaicPolygonJTS.scala	96.77% <100.00%> (+0.41%)	⬆️

... and 2 files with indirect coverage changes

[danielsparing]

For all I can tell, the failing Codecov checks are due to an earlier check (transiently?) running into calcPath == "ERROR" here, and as it is not happening in the above case, those lines are not covered anymore. So hopefully this is fine?

EDIT: here is a PR on an empty commit, with the same codecov failures, to prove the above point.

[milos-colic]

@danielsparing I have merged this, I have ignored codecoverage since it was refering error messages not being hit in an old commit.