ENH: VectorToScalar optionally extract single components.
This commit improves the user interface adding support for choosing the conversion mode.
Available conversion modes are now:
- vector (RGB, RGBA) images to luminance (default mode keeping backward compatibility with original module implementation)
- vector images to single component (user select which component to extract)
To support reusing of components by other scripted modules, a logic and widget have also been created:
- VectorToScalarVolumeConversionModeWidget
- VectorToScalarVolumeLogic
Co-authored-by: Jean-Christophe Fillion-Robin jchris.fillionr@kitware.com