Detection in a complex ROI might be unreasonably slow

[petebankhead]

See https://forum.image.sc/t/qupath-run-stardist-on-annotations-created-by-tissue-classifier/67215/2 for details.

Depending upon whether JTS internally optimizes things, the intersection calls like this one could be way more expensive that necessary.

We should also consider using OverlayNG - see:

• http://lin-ear-th-inking.blogspot.com/2020/06/jts-overlayng-noding-strategies.html
• http://lin-ear-th-inking.blogspot.com/2020/06/jts-overlayng-tolerant-topology.html