Add alt+click tests for recursive expand/collapse.
Add alt+click tests for recursive expand/collapse.

* Add tests for alt+click to recursively expand or collapse directories
* Rename keyboard related tests

samu/tree-view,atom/tree-view,tomekwi/tree-view,learn-co/learn-ide-tree,tbryant/tree-view,pombredanne/tree-view-1,cgrabowski/webgl-studio-tree-view,jasonhinkle/tree-view,laituan245/tree-view,benjaminRomano/tree-view,Galactix/tree-view,ayumi/tree-view,thgaskell/tree-view,rajendrant/tree-view-remote,matthewbauer/tree-view,jarig/tree-view