[WIP] Pim 2948 : Manage more than 100 options for an attribute type select

| Q                    | A
| -------------------- | ---
| Bug fix?             | N
| New feature?         | Y/N
| BC breaks?           | Y
| CI currently passes? | ?
| Tests pass?          | ?
| Scenarios pass?      | ?
| Checkstyle issues?*  | N
| PMD issues?**        | N
| Changelog updated?   | N
| Fixed tickets        | PIM-2948
| DB schema updated?   | N
| Migration script?    | N
| Doc PR               | 
This is my next step. I am currently working on some behat (as the feature is "working"), before cleaning and refactoring some code.