- Rename linearRingIsOriented => linearRingsAreOriented
The function checks all linear rings of a Polygon, so
the plural "rings" is more appropriate
- Rename linearRingsAreOriented => linearRingssAreOriented
The double s is appropriate because the check is done for
all Polygons of a MultiPolygon
This commit restores the function names from OpenLayers v4,
they were changed (wrongly IMHO) in #7820.