PIM-3276 UI improvements for grid column configuration

| Q                    | A
| -------------------- | ---
| Bug fix?             | N
| New feature?         | ?
| BC breaks?           | N
| CI currently passes? | ?
| Tests pass?          | ?
| Scenarios pass?      | ?
| Checkstyle issues?*  | N
| PMD issues?**        | N
| Changelog updated?   | N
| Fixed tickets        | ?
| DB schema updated?   | N
| Migration script?    | ~
| Doc PR               | ~
#target seems to be a too generic id. Maybe #attribute-bucket or something like that.