- extend RoleMapperModel with method hasDirectRole(RoleModel), which only checks for direct assignment in contrast to the existing method hasRole(RoleModel)
- extend ScopeContainerModel with method hasDirectScope(RoleModel), which only checks for direct scope mapping in contrast to the existing method hasScope(RoleModel)
- use the new hasDirectRole and hasDirectScope methods to check whether a role is in the "available" list and whether it can be assigned (previously, the hasRole method was used for this purpose)
- add hint to UI that available roles contain effectively assigned roles which are not directly assigned
- adjust and extend tests
