The case '...topMargin' was not caught for setting a relative
vertical position in GraphicHelpers. The test file demands a '7' here,
which stands for 'PAGE_FRAME'. The '7' was overwritten in GraphicImport in case
'LN_CT_Anchor_positionV' by a call of 'resolve'.

For a better overview a switch is inserted here.

Change-Id: Ie98209fe445ecbba15c3dafe5980ca52421126f8
Reviewed-on: https://gerrit.libreoffice.org/47905Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>