Allow ordering of filterable options in dropdown

[bintzandt]

Nova 4 added the option of filterable fields. Currently, it is possible to change the query that does the filtering. However, we would also like to be able to change the ordering of the options.

For example: we have a BelongsTo that references a Color. Each color has a name. We would like to add filterable to the BelongsTo. The options in the dropdown are currently sorted by their ID but in this case it makes much more sense to order them by their name.

Let me know if you have any questions :)

[ninthspace]

If you implement custom ordering of a Resource as per this:

#156 (comment)

The filterable field will be ordered.