Please add getLatLng method like google_maps_flutter

Hello :)
First off thanks for using your time to build this package!! I really appreciate it.

**Is your feature request related to a problem? Please describe.**
I'm working on a project that has a requirement to allow users to draw an area on a map.
By following [this example](https://medium.com/@shadyboshra2012/flutter-free-hand-polygon-drawing-on-google-maps-796e8bd47e85) I was able to get it to work with the google maps package. What makes this possible is the getLatLng function of the controller. It takes screen coordinate and turns them into lat/long, but the apple_maps_flutter package does not.

**Describe the solution you'd like**
It'd be great if the apple_maps_flutter package had the same getLatLng function so I could allow users to draw on the map.