Do not over grow next container if there is no space before it
Fight browser, shelf button and editor z-index
Merge branch 'file_browser_bar' into features/make-console-section-resizeable-61490090
Improve splitter

  - add splitter between file browser and editor
  - use nice tiny button for collapse/expand operations
  - extract role=browser from file browser directive template and apply
    it to directive itself otherwise splitter would not work as it adds
    CSS classes to non collapse target element that is replaced with
    template and leads to losing those CSS changes. At this moment
    i do not know better way to link splitter directive after other ones
    and priority does not help either