[core] Cleaned up Transform

Eliminated many redundant methods on Transform. Minimized usage of TransformState::x and TransformState::y. Added convenient constructors for AnimationOptions. When scaling, passing in view’s origin as the anchor no longer anchors the scaling operation at the view’s center. To specify no anchor, use NaN.

Increased precision of worldSize(), now that it’s used much more heavily in transform methods.

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/views/NativeMapView.java

@@ -264,7 +264,7 @@ final class NativeMapView {
     }
 
     public void scaleBy(double ds) {
-        scaleBy(ds, -1.0, -1.0);
+        scaleBy(ds, Double.NaN, Double.NaN);
     }
 
     public void scaleBy(double ds, double cx, double cy) {
@@ -276,7 +276,7 @@ final class NativeMapView {
     }
 
     public void setScale(double scale) {
-        setScale(scale, -1.0, -1.0);
+        setScale(scale, Double.NaN, Double.NaN);
     }
 
     public void setScale(double scale, double cx, double cy) {