PIM-2531: Filter unaccessible attributes in the product normalizer

| Q                   | A
| ------------------- | ---
| Bug fix?            | N
| New feature?        | Y
| BC breaks?          | Y
| Tests pass?         | N
| Scenarios pass?     | -
| Checkstyle issues?  | -
| Changelog updated?  | N
| Fixed tickets       | -
| Doc PR              | -

TODO: changelog, fix the broken phpunit test