Rename misnamed functions in geom/flat/orient

- 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.

src/ol/geom/Polygon.js

@@ -16,7 +16,7 @@ import {deflateCoordinatesArray} from './flat/deflate.js';
 import {inflateCoordinatesArray} from './flat/inflate.js';
 import {getInteriorPointOfArray} from './flat/interiorpoint.js';
 import {intersectsLinearRingArray} from './flat/intersectsextent.js';
-import {linearRingIsOriented, orientLinearRings} from './flat/orient.js';
+import {linearRingsAreOriented, orientLinearRings} from './flat/orient.js';
 import {quantizeArray} from './flat/simplify.js';
 import {modulo} from '../math.js';
 
@@ -266,7 +266,7 @@ class Polygon extends SimpleGeometry {
   getOrientedFlatCoordinates() {
     if (this.orientedRevision_ != this.getRevision()) {
       const flatCoordinates = this.flatCoordinates;
-      if (linearRingIsOriented(
+      if (linearRingsAreOriented(
         flatCoordinates, 0, this.ends_, this.stride)) {
         this.orientedFlatCoordinates_ = flatCoordinates;
       } else {