Sh terminology and transform improvements

Two sets of changes in subject hierarchy:

Colors and terminologies:

• Add new column for color between visibility and transform columns. It shows the color for segments, models, and markup fiducials (selected color)
• Double-clicking the color brings up terminology selector where terminology and color can be selected. Terminology information is stored in segments as before (segment attributes), and for models and markups it is stored in MRML node attributes. When selecting a terminology type, color is overwritten but name is not by default
• Terminology selector has been improved to accommodate setting terminologies to model and markup fiducial nodes, for which it's not mandatory to set terminology (unlike segments)
  • None type always appears in type list unless type search term is specified
  • Multi-select is enabled for categories, and by default all the categories are selected so that all the types show up in the types list and a search finds any type in the context
  • Expand button added to hide categories list
  • Both categories and anatomy lists are hidden by default
  • Type search box has the focus when opened and selection can be accepted by Enter press (so terminology can be selected very quickly by just typing search term then pressing Enter) Fixes https://issues.slicer.org/view.php?id=4658 Re https://github.com/PerkLab/SlicerOpenAnatomy/issues/4

Transforms:

• Transform column now shows icon instead of the first few letters of the transform name. There is a separate icon for linear and deformable transforms
• Double-clicking the icon brings up a menu instead of a node selector that had to be clicked again
• Subject hierarchy reference highlights are now updated immediately after selecting a transforms, so the highlighted transform node is always correct Re https://issues.slicer.org/view.php?id=4401