tdf#137199: sw: convert list format string to prefix/suffix for ODF
Since internally LO is able right now to use list level format strings
and prefixes/suffixes only for backward compatibility, there is a need
for conversion from format string (like "%1.") to prefix ("") and suffix
(".") still used by ODT.
Change-Id: If4b459e1b25b7f0ce511e6ac2de0824bb2c43d05
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/116288
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <thorsten.behrens@allotropia.de>