This new iteration of select-kit focuses on following best principales and disallowing mutations inside select-kit components. A best effort has been made to avoid breaking changes, however if you content was a flat array, eg: ["foo", "bar"] You will need to set valueProperty=null and nameProperty=null on the component.
Also almost every component should have an `onChange` handler now to decide what to do with the updated data. **select-kit will not mutate your data by itself anymore**
* DEV: group_list site settings should store IDs instead of group names
* Ship site setting to know when we should migrate group_list settings
* Migrate existing group_list site settings
* Bump migration timestamp and don't set null when migrating is not possible.
