Custom row class constructor in drift files

[FaFre]

For Table we have an annotation to define a constructor for custom row classes: https://drift.simonbinder.eu/docs/advanced-features/custom_row_classes/#using-another-constructor

From my research it is not possible to do this right now in combination with the WITH keyword in drift files, for table definitions, queries, etc.

Maybe we can make an annotation for the custom row class available to define the constructor to use there directly why can be consumed by the generator.

[simolus3]

Good call, I've added support for named constructors in 6bb2c3d.