fix(views): Stages UI

+ Move 'views' in archive filter sidepane
+ Make stages part of 'desks' service
+ Create StagesCtrl for handling
+ Create sd-desk-stages directive to display stages within specific desk
+ Make 'Content' and 'Task' aware of stages

SD-914, SD-903, SD-904
in general i think it's more readable to use `<button translate>Clear</button>`