Improvements in properties UI structure

[RaphaelAlvez]

working on #2269 I came acros some features missing or some stuff I think could be better:

• preview buttons should be able to have a title
  

• preview buttons should be resizable (to much lost space in the previous example

• We need some headers structure. in this example it would be nice to have all the properties into the same section but with sub titles
  

• preview buttons don't update when you change some other property

• some properties should always be displayed (example activeFace in dice)

  • these properties should show the default value instead of null when not defined

• color input type is missing