[Repository] Item tree output as tree

[jc7447]

Improve item tree output to looks like a tree with sub-level representation.

Item A
-- Sub item B
---- Sub Sub Item G
-- Sub item C
---- Sub sub item D
------ Sub sub ...
Item E
-- Sub Item F

[jc7447]

This can be nice :
http://visjs.org/examples/network/nodeStyles/HTMLInNodes.html

We could create an svg image from each data tab and link all image as the example.