vacuumdb: Allow specifying objects to process in all databases.
Presently, vacuumdb's --table, --schema, and --exclude-schema
options cannot be used together with --all, i.e., you cannot
specify tables or schemas to process in all databases. This commit
removes this unnecessary restriction, thus enabling potentially
useful commands like "vacuumdb --all --schema pg_catalog".
Reviewed-by: Kyotaro Horiguchi, Dean Rasheed
Discussion: https://postgr.es/m/
20230628232402.GA1954626%40nathanxps13