Split apart message_level_options into one set for server-side settings and one for client-side, restoring the previous behaviour with different sort order for the 'log' level. Also, remove redundant list of available options, since the enum code will output it automatically.
Split apart message_level_options into one set for server-side settings and
one for client-side, restoring the previous behaviour with different
sort order for the 'log' level. Also, remove redundant list of available
options, since the enum code will output it automatically.

xinzweb/gpdb,oberstet/postgres-xl,Chibin/gpdb,zeroae/postgres-xl,greenplum-db/gpdb,zeroae/postgres-xl,jmcatamney/gpdb,yuanzhao/gpdb,edespino/gpdb,oberstet/postgres-xl,adam8157/gpdb,yuanzhao/gpdb,ashwinstar/gpdb,adam8157/gpdb,yuanzhao/gpdb,Postgres-XL/Postgres-XL,50wu/gpdb,Postgres-XL/Postgres-XL,greenplum-db/gpdb,zeroae/postgres-xl,greenplum-db/gpdb,Postgres-XL/Postgres-XL,ashwinstar/gpdb,postmind-net/postgres-xl,50wu/gpdb,adam8157/gpdb,techdragon/Postgres-XL,arcivanov/postgres-xl,ovr/postgres-xl,xinzweb/gpdb,edespino/gpdb,jmcatamney/gpdb,Chibin/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,arcivanov/postgres-xl,zeroae/postgres-xl,kmjungersen/PostgresXL,kmjungersen/PostgresXL,xinzweb/gpdb,greenplum-db/gpdb,lisakowen/gpdb,50wu/gpdb,yuanzhao/gpdb,xinzweb/gpdb,xinzweb/gpdb,arcivanov/postgres-xl,adam8157/gpdb,techdragon/Postgres-XL,edespino/gpdb,edespino/gpdb,Postgres-XL/Postgres-XL,lisakowen/gpdb,Chibin/gpdb,kmjungersen/PostgresXL,yazun/postgres-xl,pavanvd/postgres-xl,snaga/postgres-xl,ashwinstar/gpdb,Chibin/gpdb,tpostgres-projects/tPostgres,Postgres-XL/Postgres-XL,ovr/postgres-xl,yazun/postgres-xl,50wu/gpdb,xinzweb/gpdb,yazun/postgres-xl,edespino/gpdb,pavanvd/postgres-xl,arcivanov/postgres-xl,tpostgres-projects/tPostgres,jmcatamney/gpdb,postmind-net/postgres-xl,kmjungersen/PostgresXL,Chibin/gpdb,snaga/postgres-xl,greenplum-db/gpdb,techdragon/Postgres-XL,techdragon/Postgres-XL,greenplum-db/gpdb,arcivanov/postgres-xl,snaga/postgres-xl,jmcatamney/gpdb,lisakowen/gpdb,50wu/gpdb,ovr/postgres-xl,greenplum-db/gpdb,yuanzhao/gpdb,adam8157/gpdb,ashwinstar/gpdb,adam8157/gpdb,edespino/gpdb,pavanvd/postgres-xl,edespino/gpdb,yuanzhao/gpdb,edespino/gpdb,Chibin/gpdb,xinzweb/gpdb,tpostgres-projects/tPostgres,lisakowen/gpdb,edespino/gpdb,ovr/postgres-xl,oberstet/postgres-xl,edespino/gpdb,yazun/postgres-xl,ashwinstar/gpdb,jmcatamney/gpdb,lisakowen/gpdb,ashwinstar/gpdb,lisakowen/gpdb,adam8157/gpdb,ashwinstar/gpdb,yuanzhao/gpdb,arcivanov/postgres-xl,snaga/postgres-xl,50wu/gpdb,tpostgres-projects/tPostgres,Chibin/gpdb,xinzweb/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,yuanzhao/gpdb,oberstet/postgres-xl,ovr/postgres-xl,zeroae/postgres-xl,postmind-net/postgres-xl,postmind-net/postgres-xl,tpostgres-projects/tPostgres,Chibin/gpdb,50wu/gpdb,yazun/postgres-xl,lisakowen/gpdb,Chibin/gpdb,pavanvd/postgres-xl,Chibin/gpdb,kmjungersen/PostgresXL,postmind-net/postgres-xl,jmcatamney/gpdb,jmcatamney/gpdb,oberstet/postgres-xl,pavanvd/postgres-xl,lisakowen/gpdb,snaga/postgres-xl,50wu/gpdb,greenplum-db/gpdb,techdragon/Postgres-XL,adam8157/gpdb