PIM-2135 Manage Media with MongoDB

| Q                   | A
| ------------------- | ---
| Bug fix?            | no
| New feature?        | no 
| BC breaks?          | no
| Tests pass?         | no
| Scenarios pass?     | 740
| Checkstyle issues?  | ?
| Changelog updated?  | no
| Fixed tickets       | PIM-2135
| Doc PR              |