feat(layout): add `LayoutPolar` #98

Job	Run time
Clippy	2m 1s
semver	53s
Build Book	1m 39s
Rustfmt	16s
Tests (windows-latest, chrome, plotly_ndarray,plotly_image,static_export_chromedriver,debug)	6m 54s
Build Wasm Examples (callback-example)	55s
Tests (ubuntu-latest, firefox, plotly_ndarray,plotly_image,static_export_geckodriver,static_expor...	3m 20s
Tests (ubuntu-latest, chrome, plotly_ndarray,plotly_image,static_export_default,debug)	3m 11s
Build Wasm Examples (basic)	1m 6s
Build Examples (financial_charts)	32s
Code Coverage	13s
Build Examples (scientific_charts)	32s
Build Examples (kaleido)	1m 24s
Build Examples (themes)	32s
Build Examples (basic_charts)	37s
Tests (macos-latest, chrome, plotly_ndarray,plotly_image,static_export_default,debug)	2m 28s
Build Examples (maps)	42s
Build Examples (customization/density_mapbox_example)	30s
Build Examples (custom_controls)	36s
Build Examples (images)	44s
Build Examples (3d_charts)	35s
Build Examples (customization/multiple_plots_example)	29s
Build Examples (shapes)	31s
Build Examples (subplots)	30s
Build Examples (statistical_charts)	28s
Build Examples (ndarray)	46s
Build Examples (customization/consistent_static_format_export)	1m 24s
	33m 48s

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