MapMarker constructor
      const
      MapMarker({})
     
    
Creates a MapMarker.
Implementation
const MapMarker({
  Key? key,
  required this.latitude,
  required this.longitude,
  this.size,
  this.alignment = Alignment.center,
  this.offset = Offset.zero,
  this.iconColor,
  this.iconStrokeColor,
  this.iconStrokeWidth,
  this.iconType = MapIconType.circle,
  Widget? child,
}) : super(key: key, child: child);