Add a more intuitive icon and a tooltip
Add a more intuitive icon and a tooltip

Signed-off-by: Marcus D. Hanwell <cf7042e2e8eee958b5bcde1ae2cbefef82efc184@kitware.com>

OpenChemistry/tomviz,OpenChemistry/tomviz,OpenChemistry/tomviz,OpenChemistry/tomviz