Improve typescript definitions (#2012)
Improve typescript definitions (#2012)

* Improve typescript definitions

* MapPolygonProps coordinates should be required as per documentation
* MapPolylineProps coordinates should be required as per documentation

**Specify that these functions have a argument and what type they are:**
* onRegionChange
* onRegionChangeComplete
* onPress
* onLongPress
* onPanDrag
* onMarkerDragStart
* onMarkerDrag
* onMarkerDragEnd

* Add missing prop and function types for Marker

zigbang/react-native-maps,wannyk/react-native-maps,lelandrichardson/react-native-maps,lelandrichardson/react-native-maps,zigbang/react-native-maps,lelandrichardson/react-native-maps,wannyk/react-native-maps,wannyk/react-native-maps,wannyk/react-native-maps,zigbang/react-native-maps