Add tokens for 'table row' redlines (future patch)

This patch adds 2 tokens for future patche's use of table row
redline preservation.

Change-Id: I20e6d1dd84a07f515076aaa3cd5b32c492ec476d
Reviewed-on: https://gerrit.libreoffice.org/7801
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>