PIM-3276 UI improvements for grid column configuration

| Q                    | A
| -------------------- | ---
| Bug fix?             | N
| New feature?         | Y
| BC breaks?           | N
| CI currently passes? | almost
| Tests pass?          | Y
| Scenarios pass?      | Y
| Checkstyle issues?*  | N
| PMD issues?**        | N
| Changelog updated?   | N
| Fixed tickets        | PIM-3269, PIM-3270, PIM-3271, PIM-3272, PIM-3273, PIM-3276
| DB schema updated?   | N
| Migration script?    | ~
| Doc PR               | ~
ok, will do that then