Add accordians for all elements with children (group/fragment/mesh/etc)

[tryptefan]

Add support for expanding and collapsing groups or maybe anything with children (ie: meshes)

[itsdouges]

@tryptefan currently there exists accordians for elements that have components inside them, but not for components that have them as direct children, e.g:

<Box> // will have an accordian for the elements inside it (mesh)
  <meshStandardMaterial /> // will not be inside an accordion
</Box>

Any thoughts around the UI/UX that would need to change to enable both to have accordions?

[tryptefan]

I love the accordions on parent components. I was expecting to see the exact same UX on the children who themselves have children: > Mesh
Same for a group...I expected an arrow next to my group.