Add the option to not draw polygon boundaries in the map

[maciejjan]

We decided in the slack discussion not to implement it for the time being as it produces misleading maps - looking like density maps, but not being such. In the map above, southwestern Finland contain many small parishes with small values (number of distinct types per parish) - if grouped into larger areas, they could have larger values (comparable to those in the east), but in the map they show just as one contiguous small-valued region, giving the misleading impression that the value 1-118 distinct types is for the whole pale-colored field together.

[maciejjan]

It was decided in a meeting to not implement it.