Add MGLPointCollection for GeoJSON multipoints (#6742)

* [ios, macos] Introduce MGLPointCollection

This makes MGLMultiPoint abstract again so that it is only a place 
for shared functionality of polygons and polylines. The multipoint 
feature replaces the point collection feature and can be
used to initialize a MGLGeoJSONSource. The previously added 
swift_names for polyline and polygon are removed, for now.

This also updates the iOS and macOS annotation adding logic so that
unwanted shapes really are avoided. Previously the combined OR
conditions  meant that an annotation had to logically be NOT a kind
of all three types so the check always let the annotation slip through.
This also expands the guard to deflect the new MGLPointCollection.

1 files changed, 4 insertions, 5 deletions

diff --git a/platform/ios/src/MGLMapView.h b/platform/ios/src/MGLMapView.h
index 57b74daa04..5a89632db8 100644
--- a/platform/ios/src/MGLMapView.h
+++ b/platform/ios/src/MGLMapView.h
@@ -895,11 +895,10 @@ IB_DESIGNABLE
 /**
  Adds an annotation to the map view.
  
- @note `MGLMultiPolyline`, `MGLMultiPolygon`, and `MGLShapeCollection` objects
-    cannot be added to the map view at this time. Nor can `MGLMultiPoint`
-    objects that are not instances of `MGLPolyline` or `MGLPolygon`. Any
-    multipoint, multipolyline, multipolygon, or shape collection object that is
-    specified is silently ignored.
+ @note `MGLMultiPolyline`, `MGLMultiPolygon`, `MGLShapeCollection`, and 
+    `MGLPointCollection` objects cannot be added to the map view at this time. 
+    Any multipoint, multipolyline, multipolygon, shape or point collection 
+    object that is specified is silently ignored.
  
  @param annotation The annotation object to add to the receiver. This object
     must conform to the `MGLAnnotation` protocol. The map view retains the