Non Maxima Suppression
What is included in this PR?
- two versions of the non-maxima suppression algorithm:
- a 'naive' version that filters all overlapping boxes
- a "class aware" version of the algorithm that only filters overlapping boxes of the same class.
- this helps to properly detect drawers and their handles, which might share a significant amount of overlap, but should not be filtered, as the drawer handle must overlap to some extent