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, 6 insertions, 15 deletions

diff --git a/platform/darwin/src/MGLMultiPoint.h b/platform/darwin/src/MGLMultiPoint.h
index b936205ab2..69c7295842 100644
--- a/platform/darwin/src/MGLMultiPoint.h
+++ b/platform/darwin/src/MGLMultiPoint.h
@@ -6,25 +6,16 @@
 NS_ASSUME_NONNULL_BEGIN
 
 /**
- The `MGLMultiPoint` class is used to define shapes composed of multiple points. 
- This class is also the superclass of `MGLPolyline` and `MGLPolygon`. The
- methods and properties of this class can be used to access information about 
- the specific points associated with a line or polygon.
+ The `MGLMultiPoint` class is an abstract superclass used to define shapes
+ composed of multiple points. You should not create instances of this class
+ directly. Instead, you should create instances of the `MGLPolyline` or
+ `MGLPolygon` classes. However, you can use the method and properties of this
+ class to access information about the specific points associated with the line
+ or polygon.
  */
 @interface MGLMultiPoint : MGLShape
 
 /**
- Creates and returns an `MGLMultiPoint` object from the specified set of
- coordinates.
- 
- @param coords The array of coordinates defining the shape. The data in this
- array is copied to the new object.
- @param count The number of items in the `coords` array.
- @return A new multipoint object.
- */
-+ (instancetype)multiPointWithCoordinates:(CLLocationCoordinate2D *)coords count:(NSUInteger)count NS_SWIFT_NAME(multiPoint(coordinates:count:));
-
-/**
  The array of coordinates associated with the shape.
  
  This C array is a pointer to a structure inside the multipoint object,