ICONS: add large icons for .uno:GraphicDialog for use in image toolbar

Change-Id: Ie1a4fc49521c5e08f80a3265ec6f24463b944cde
Reviewed-on: https://gerrit.libreoffice.org/13507
Reviewed-by: Yousuf Philips <philipz85@hotmail.com>
Tested-by: Yousuf Philips <philipz85@hotmail.com>