Allow SQL expressions in `@orderBy`

What problem does this feature proposal attempt to solve?

This feature would allow requests to be sorted by null column values.

In example : to order a list of DateTime in SQL, providing
ISNULL(created_at) ASC, created_at ASC
allows date to be ordered right after non-null date values.

For the moment, it's only possible to do it by setting a @builder directive, and chain a raw SQL ordering. So it's ok when ordering on a simple table, but this is not as easy with a relation ordering

Which possible solutions should be considered?

In the OrderByDirection enum, maybe add 2 attributes ? NULL_ASC and NULL_DESC ? I'll stick to what is the simplest implementation to you guys

(and once again, thank's for the package)

Start by tracing the @orderBy directive and the OrderByDirection enum, then compare the existing builder-directive approach with relation ordering. The issue does not name specific files or tests. Done means requests can express SQL ordering for null values, including relation ordering, without requiring a separate builder directive.