Added UTS to verify the series names (Labels) for chart series for following-
    * xls, xlsx, ods
    * odt

Change-Id: I4575a2e7ada9d4cf8b3fa708bd313f9d16244f65
Change-Id: Id291b49bf7547ee7264eb7c0751e416d20ca1e54
Reviewed-on: https://gerrit.libreoffice.org/6383Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>