Return Units instead of Float in GeodesicUtils

Example:

```st
distanceInM := GeodesicUtils distanceInMetersFrom: anObject absoluteCoordinates to: anotherObject absoluteCoordinates.
distanceInNM:= distanceInM / 1852.
```

become:
```st
distance := GeodesicUtils distanceFrom: anObject absoluteCoordinates to: anotherObject absoluteCoordinates.
distanceInNM:= distance nauticMile.
```