XclTools::GetBuiltInDefNameIndex(...) only checked for prefix used in
binary Excel format, and didn't recognize OOXML built-in names, which
resulted in saving them twice in OOXML files.

Adapt to check both binary and OOXML prefixes, similarly to
XclTools::IsBuiltInStyleName(...).

Saving "bad" files after the fix will purge bad "_0", "_0_0" etc.
suffixed built-in names due to how GetBuiltInDefNameIndex(...) works.

Change-Id: I1bbe11f9c654a142a4626003df4cb0fd2a0f9c71
Reviewed-on: https://gerrit.libreoffice.org/45381Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>
(cherry picked from commit f8b9d0fb)
Reviewed-on: https://gerrit.libreoffice.org/45700Tested-by: Jenkins <ci@libreoffice.org>