implemented minZoom/maxZoom for Android and iOS

[felixkrautschuk]

[Yermo]

Thank you for this. I apologize it's taken me so long to get to it.

The plan for nativescript-mapbox is to move it towards being API compatible to the degree possible with mapbox-gl-js.

I was wondering if I could trouble you to update the API calls to match their equivalents in mapbox-gl-js?

e.g. https://docs.mapbox.com/mapbox-gl-js/api/map/#map#setmaxzoom

[felixkrautschuk]

@Yermo I renamed the minZoom/maxZoom methods according the mapbox-gl-js namings, so

setMaxZoomLevel -> setMaxZoom setMinZoomLevel -> setMinZoom getMaxZoomLevel -> getMaxZoom getMinZoomLevel -> getMinZoom