Formation Names: Color cells based on Formation Name grouping (Odb cases)

[JacobStoren]

• Introduce a new result type: Formation Layers in the Color Results / Cell Results properties
  (In addition to Nodes, Elm Nodes and Integration Points, for odb cases and
  Static, Dynamic, Generated, for eclipse cases)
• Show the selected "Fomation Name Set" selected on the Case (See Formation Names: Display the formation name of a Cell in result info when selected (Odb Cases) #810) as static information
• Use a category-legend to color the cells based on their Formation Name

It would possibly be a sensible extension to display a list of the available Formation Name Sets, instead of just showing the one selected on the Case.