Move the databases-ddl internal package to the new compass-databases-ddl repo.

• Move all code from internal-packages/database-ddl to 10gen/compass-databases-ddl
• Use the khaos template to generate the plugin and make necessary changes to the template if problems arise.
• Move all databases-ddl tests from Compass to the compass-databases-ddl repo
• Add compass-databases-ddl to the compass-lite and compass-enterprise distribution configs in the package.json in Compass (for now)
• Remove internal-packages/databases-ddl