Model test fixtures as a propert artifact Previously they were modeled as just a file collection, which confused the IDEA importer. They now use the more canonical way of defining an additional artifact.
In a next step they should be reimplemented using variant aware dependency resolution, so that we don't need a special DSL to declare these dependencies.
Convert dependency management related subprojects to kotlin-dsl (#4498) This PR also fixes the dependency declarations wrt. api/impl separation for these and related projects. It fixes two places in production/test code where dependencies leaked into the classpath and the wrong classes where imported.