Improve Docker based setup _ Make CentOS based images more resilient against package installation problems _ Upgrade database image to Debian bullseye to avoid OpenSSL bug that prevented downloading demo data and do some cleanup in passing _ Add docker-compose file for more automated setup

select.abflusstafel = \
    SELECT ABFLUSSTAFEL_NR, \
           ABFLUSSTAFEL_BEZ, \
           GUELTIG_VON, \
           GUELTIG_BIS, \
           PEGELNULLPUNKT, \
           AT.BFG_ID \
    FROM ABFLUSSTAFEL AT \
    WHERE MESSSTELLE_NR LIKE :number