WIP: Tri-view processor

This processor will allow a user to draw a ROI around the sample; this
will exclude detections within the sample volume, and later black out the
pixels beyond the sample volume.

Signed-off-by: Luke Stuyvenberg <stuyvenberg@wisc.edu>
BeadProcessor: Add filtering capability

(This needs to be moved before the tri-view)

Signed-off-by: Luke Stuyvenberg <stuyvenberg@wisc.edu>