Antimeridian problem

[aabelean]

• Summary of changes (Bug fix, feature, docs update, ...) Solves the antimeridian problem in mapping: split all polygons that cross the dateline/antimeridian. Added this function as optional for plot_map because the user-defined polygons might be too complex and cause errors.

• Please check if the PR fulfills these requirements

• [x] Closes #225

• [x] Tests added and passed

• [x] All code checks passing - styler run over code

• [x] Added an entry in the latest CHANGELOG.md file if fixing a bug or adding a new feature

• [x] Any new libraries added to DESCRIPTION

[aabelean]

I wonder if it now works. Tests seem to fail because the functions do not yet appear in NAMESPACE.

Thank you @aabelean. Both plot_mapping.R and plot_mesh.R work ok, but shiny_meshbuilder.R returns an error when testing it with the covid19 data. The error is attached below.

[aabelean]

Thanks for checking, @XueqingYin .