Add unit-tests for DOCX preservation of 'table row redline'

Added unit-tests to make sure that 'table row redlines'
(e.g. - table row was inserted \ removed) are being round
tripped correctly from a DOCX file.

Change-Id: I369dd32e7372d0cf0add19197f07d0ad604e9ef0
Reviewed-on: https://gerrit.libreoffice.org/7849
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>