ENYO-3375: Add 2 buttons to expand or collapse all categories of the designer's palette

Related JIRA: https://enyojs.atlassian.net/browse/ENYO-3375

Categories of the designer's palette can be all expanded or collapsed together
It replaces https://github.com/enyojs/ares-project/pull/658 PR

Enyo-DCO-1.1-Signed-off-by: Vincent HERILIER vincent.herilier@hp.com