[Client] Use MultiSelect with SelectAll and CheckBox
Change MultiSelect component to adopt one that displays the list with checkbox and supports a select-all for the Category search component.
This avoids to have an input box that grows to much when adding multiple categories.
New Component still supports clear-all.
Proposal following #1009 (closed)
Few screenshots to give some flavor of the change:
There are still some little visual glitches that may be improved to comply fully with Kresus look&feel but it is beyond my knowledge (CSS tricks)