This reverts commit 2570a103.

BIS-753: Working on the bar with disk space. Planed the indicator on the same line with the navigation bar.

BIS-1018: handle unsaved changes on ImagingDatasetViewer and store&load display settings in ImagingGalleryViewer

BIS-753: Working on attaching the DSS widget to a concrete collection/object. Fixed the problem with listing files for an entity that has no folder on the FS.

BIS-753: Working on attaching the DSS widget to a concrete collection/object. Fixed the problem with listing files for an entity that has no folder on the FS.