fix(geojson): simplify loop rewinding

fix(geojson): ignore zero area geometries

fix(geojson): hot path optimization

fix(geojson): hot path optimization

fix(geojson): avoid global coverings for invalid geometries

fix(geojson): detect invalid polygon loops

feat(s2): cellid

fix(geojson): strip duplicate adjacent polygon ring vertices

fix(geojson): RegionCoverer

Remove optimization which failed to enforce minLevel constraint

feat(geojson): Rect encoding