Improve sample and materials handling in GUI

From the recent discussion and application of BA GUI to model "lipid bilayer on Si crystal with SiO2 nanoparticles"

• show material name for particles
• hide magnetization by default as it can be easily confused with the particle offset
• allow shell offset in Core-Shell model
• automatically suggest e-06 for the new materials, for example in a separate spinbox
• review truncation parameters: UntruncatedHeight, Delta height, Height flattening are unclear to the user. Maybe just Top cut, Bottom cut, Horizontal radius, Vertical radius?
• ease distingushing particle groupboxes from each other. Slightly change color, assign name?
• Interference function None: replace with Disorder or Random