oox: fix export of BezierShapes in DOCX

Change-Id: I6fce580fc68c9ab2a56e342d6c5473f46e9a7f56
oox: fix export of LineShapes in DOCX

Change-Id: I7b6f4616d450d2cffa58217db2ef250f5b8d9cba
oox: fix export of TextShapes in DOCX

This was the last shape type that unconditionally wrote XML_sp for the
shape element, which is invalid for DOCX.

Change-Id: I3a6f8e6fd8ebbe663dce9ed4453396c3ec91c38a