Support CircularString and CircularRing

[sunshine0576]

such as geometry = 'CIRCULARSTRING(1 1, 2 0, -1 1)'

[jnh5y]

@dr-jts I don't mean to disagree with closing this ticket. For future reference, do we want JTS 1.x to support these extended types? And if not, is it something worth discussing for JTS 2.0?

For folks looking for this support, I'd note that GeoTools does have a WKTReader that will handle arcs. Not sure how geometric/topological operations are handled with those geometries.

[dr-jts]

I guess some would like to see this supported. It's quite a bit of work, so absent budget and resources it's unlikely to get done soon.

I did label this with the FUTURE milestone, with the idea that it wouldn't get lost.