Modified build.gradle to have tasks for migrating both types of DB

[Khushal/Priti] Modified build.gradle to have tasks for migrating both types of DB. Added migrateDB and showDBInfo with params as DB name. They wrap over flyway so that one can pass DB name as param. Also seperated the migration folder into list_db and core_db so that migrations for tenant list and core tenent db can be placed in different folders.


gradle migrateDB -PdbName=mifosplatform-tenants -PmigrationScriptFolder=list_db

gradle migrateDB -PdbName=mifostenant-default -PmigrationScriptFolder=core_db