Split worker database configuration

Qserv configuration tool now configures
worker database apart from master database.
Previous code was creating both czar and
worker databases on both czar and worker
MySQL instances.
Factorize SQL loader for czar/worker configurations

Qserv czar and worker configurations are now distinct
procedures, but they use the same script to load
sql files related to czar and worker databases.
Sharpen SQL scripts for worker and czar configuration

SQL scripts launched by configuration tool for czar
and worker now create the right tables at the
right place, with more accurate permissions.