The situation is the following: we have a text frame, with at least two
anchored objects: one is wrapped not-wrap-through, the other is. In case
the non-wrap-though one shifts the text content of the text frame right or
down, then layout may or may not want to re-consider what is the top
left corner of the text frame for anchoring purposes.

Regarding the x position, sw layout repositioned the anchor point
depending on the AddFrameOffsets compat mode: it's enabled for documents
imported from Word, disabled otherwise.  Regarding the y position, no
repositioning was done, however the bugdoc shows that Word does the same
repositioning on the vertical axis as well.

Add a new AddVerticalFrameOffsets compat mode that enables vertical
repositioning as well, and enable that mode for documents imported from
DOCX.

Change-Id: Idc5cad7d86662008a92ff3bf5fbb3806aa2c7b07
Reviewed-on: https://gerrit.libreoffice.org/23702Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins <ci@libreoffice.org>