Samples: extract TreeTable on its own?

I was looking for TreeTable among samples but couldn’t find it. Turns out it’s under DataTable (why not under Tree?).

Since TreeTable is a component on its own, maybe it would be good to extract its samples out of DataTable and into the main samples directory?

TreeTable has all functionality of DataTable + some methods of Tree.

Sample navigation will be changed anyway, current one is too confusing and hard for new comers.