oox: fix XML namespace of drawing::GraphicObjectShape in DML export

Change-Id: Ia7fb126f30ff1c4cd2f5fb8a5c71a87dd5e1d5c9
oox: handle pic:pic in WPG groupshape import

Change-Id: I7de11251bc4e1b58f9cb308e8b698d4c8c1a58d3