Visibility scaling for UDDF import

Visibility is defined in meters in UDDF and we use scale up to 5 stars.
Thus the meters are scaled to our star rating using one-size-fits all
method.

< 1m => 1 star
<= 3m => 2 star
<= 5m => 3 star
<= 10m => 4 star
> 10m => 5 star

Signed-off-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>