Object detection (e.g. words_detect_v2) does not support "best" or "top" N

[cchadowitz]

From the conversation in Gitter, it would be helpful if object detection that produce bounding boxes like words_detect_v2 could somehow be filtered to output the top or best N detections. @beniz suggested this could be done as a chain filter. Creating this issue to track it.

[beniz]

@cchadowitz-pf thanks, I've updated the scope to object detection at large, i.e. with more than a single class, since this is a demand we hear from several sources now.

I'm also about to revise my strict semantics on the best parameter :)

[cchadowitz]

Haha, awesome! It would be cool if the best parameter had optional configurations 🙃