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?          | Y
| Scenarios pass?      | ?
| Checkstyle issues?*  | N
| PMD issues?**        | N
| Changelog updated?   | Y
| Fixed tickets        | PIM-2948
| DB schema updated?   | Y
| Migration script?    | Y
| Doc PR               | 

Left to do : 

- [ ] Use a dedicated serializer for 'UI' serialization
- [x] Create an attributeOptionMananger
- [x] Localize javascript errors
- [x] Add the "Save first before add any options"
- [x] Improve the oading on first load
Not really. This explicitly waits for something to fire ajax requests within 2 secs, then waits for the requests to complete.