add point cloud support to_spherical

[bjlittle]

🚀 Pull Request

Description

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[codecov]

Codecov Report

Merging #285 (639d4e9) into main (9a0601c) will increase coverage by 1.57%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #285      +/-   ##
==========================================
+ Coverage   53.33%   54.91%   +1.57%     
==========================================
  Files          31       32       +1     
  Lines        2066     2136      +70     
==========================================
+ Hits         1102     1173      +71     
+ Misses        964      963       -1     

Impacted Files	Coverage Δ
src/geovista/common.py	73.73% <100.00%> (+1.77%)	⬆️
tests/common/test_to_spherical.py	100.00% <100.00%> (ø)
tests/conftest.py	100.00% <100.00%> (ø)
tests/geometry/test_load_coastlines.py	100.00% <100.00%> (ø)