tdf#116883: sw: support for lists level format string

tdf#116883: sw: support for lists level format string

Multilevel lists are more flexible in case of DOCX. There is
supported custom format for any level in DOCX unlike in LO
and ODT where we are limited only with prefix and suffix
for hardcoded list levels separated by dot. At the same time
DOCX can have lists not only "1.2.3.4", but "1/2/3/4" or even
"1!2>3)4" and such format can vary on each list level.

Here is basic implementation for list format as a core feature
for all documents and old way (prefix-suffix + ".") is left
as fallback.

Practically its usage is currently implemented only in DOCX
import/export.

Some RTF/OOXML unittests were redesigned: since we are not creating
prefix/suffix for these formats conditions should be checked in
a different way.

Change-Id: I1ec58bcc5874d4fa19aee6a1f42bf1671d853b14
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/92106
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/93125
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
Change-Id: Ia8f066913a2565559d81f3caabeba24b29c09052
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/93456