DOCX import: handle wp14:sizeRelH/V relativeFrom=margin

No explicit code for this was necessary in case for TextFrames, but for
drawinglayer shapes the default is relativeFrom=page. To keep things
simpler, just always set these, regardless what the LO default is.

Change-Id: I9f651d7cce4a12ce7f545e42656b92d078a74327
DOCX export: handle wp14:sizeRelH/V relativeFrom=margin for shapes

Change-Id: I913fe328376a246bf410512c4cfb018fc573094b