drawingML import: paragraph spacing inside group shape

unotext: a conversion was missing during the corresponding
SvxLineSpacingItem was filled with "ParaLineSpacing" UNO property.

Change-Id: I02559ed7e8b46150a88eed2bf20afdf084aec47b
DOCX export: remove some extra pPr tag

StartParagraphProperties and EndParagraphProperties
contains these lines.

Change-Id: I05cceb64cfa8c2b1673d44009ef1914fcf7f3e6d
WW export: make line spacing export clearer

see also: SvxLineSpacingItem::PutValue

Move para spacing test from import to export and
remove a test case which tests a part of the same thing.

Change-Id: I96da9f6ac7851bd74e34ab4a6d2a2f3499549a87