Move Harvester DB settings from Common to Harvester module

The harvester database specific settings:

1. DB_SPECIFICS_CLASS = "settings.common.database.class"
2. DB_IS_DERBY_IF_CONTAINS = "Derby"
3. DB_BASE_URL = "settings.common.database.baseUrl"
4. DB_MACHINE = "settings.common.database.machine"
5. DB_PORT = "settings.common.database.port"
6. DB_DIR = "settings.common.database.dir"
7. DB_CONN_VALID_CHECK_TIMEOUT = "settings.common.database.validityCheckTimeout";
   are currently part of the common settings. They should be moved to the harvester module settings.
   The DB_CONN_VALID_CHECK_TIMEOUT is still used by the Admin DB in the Archive module so this settings needs to be split into a harvester DB and an Archive DB specific settings.