ENH: Added option to control the PropagateVolumeSelection behavior
Created by: mehrtash
Added the following features:
- Volume selection can propagate selectively to background, foreground and label layers.
- HelperBox and EditUtil were modified to use the new propagation mode. Default mode will propagate through all layers while "BackgroundAndLabel" mode only propagates to background and label and doesn't touch foreground.
This feature is useful in cases where different foregrounds are set to different views and we don't want editor to reset foregrounds through propagate volume selection. A use case is the ongoing project PCampReview [1].
[1] PCampReview