Added Cartesian2.cross which computes the magnitude of the cross product of two vectors whose Z values are implicitly 0.

Added BillboardCollection.show, EntityCluster.show, LabelCollection.show, PointPrimitiveCollection.show, and PolylineCollection.show for a convenient way to control show of the entire collection.

Removed Cesium3DTileset.url, which was deprecated in CesiumJS 1.78. Use Cesium3DTileset.resource.url to retrieve the url value.

Removed EasingFunction.QUADRACTIC_IN, which was deprecated in CesiumJS 1.77. Use EasingFunction.QUADRATIC_IN.
Removed EasingFunction.QUADRACTIC_OUT, which was deprecated in CesiumJS 1.77. Use EasingFunction.QUADRATIC_OUT.
Removed EasingFunction.QUADRACTIC_IN_OUT, which was deprecated in CesiumJS 1.77. Use EasingFunction.QUADRATIC_IN_OUT.