Project Bostadstyp (housing form) on update project API

Changes to the API since 039.

Added

housingForm is now supported on Update a project, allowing broker systems to set a project's Bostadstyp when updating project information.

The field accepts the same integer housing form codes used for listings and project units.

Changed

Project update requests that include an invalid housingForm value now return a validation error before the request is sent to CoreAPI.