Support basic current location indicator

[JulianBissekkou]

Some apps require to display the users location on the map.
Example:

JS Documentation:
https://developers.arcgis.com/javascript/latest/tutorials/display-your-location/

iOS:
https://developers.arcgis.com/swift/device-location/

Android:
https://developers.arcgis.com/kotlin/device-location/

Additionally, it would be nice to create a custom location source that provides location for the indicator in case your app is already accessing locations.

[JulianBissekkou]

I will start with an initial draft on mobile.

[JulianBissekkou]

Implemented in #69