Expand/collapse sidebar branches by double-click

[rat-moonshine]

For quite some time in sidebar tree component, one thing annoying me - single-click expand/collapse branches in the tree. Although this looks handy by expanding/collapsing branches by single-click only, sometime, when working rapidly through the tree file systems, this became annoying when a selection click also expand/collapse a branch icon even when that was not intended to. The effect reasons another click to expand/collapse the branch folder.

[rat-moonshine]

Expand/collapse of tree branches now limited to following events:

• Double-click on branch row item
• Single-click on tree disclosure (arrow) icon as it was always