ENYO-3570: change folder nodes opening behaviour

Related JIRA: https://enyojs.atlassian.net/browse/ENYO-3570

change folder nodes opening behaviour: folders are now opened by clicking on node icon and double-clicking on node label in every filetree

Enyo-DCO-1.1-Signed-off-by: Vincent HERILIER vincent.herilier@hp.com