Create Mobile Friendly display mode for Treeview

[stephenwhippuk]

The Tree View currently is fine for larger displays, however it isn't friendly for mobile screens

A by folder view mode is required

• this should allow the user to see the contents of only 1 folder at a time to select, but navigate through them through selection of folder and a '..' option
• there should be a breadcrumb to show the path to the folder they are in
• it should allow for correct dynamic switching if the screen is resized (when swapping to folder view) the current folder is the one containing the currently viewed file OR the last manipulated node in the event of there being no selected file.

[stephenwhippuk]

Rethink on this we may be able to get away with just a show tree view button and moving it up a layer with media queries

This would be tbe preferable option if it works.