Introduce support for importing a VSP which contains data types which are specific to the package being imported, i.e. the types are previously unknown to the system

the new types are to be created in the DB and connected to a new model instance which is also to be created in the DB to represent the model applicable to the package.

This new model instance shall be considered an extension of the model selected during VSP onboarding. An edge shall be created in the DB between the two model instances, with queries on the model taking the relationship into consideration