Tenant admin determines installer authorization

Short characteristics
- Installers, who for example completed a training course, are added to the user list.
- The Tenant Administrator adds the authorized installer to a reference plant.
Privileges
- The roles of installers and end users are designed as follows:
- Entitled, to set up end users.
- Not entitled to set up additional installers (this limitation is only possible as a regulation at this time).
- Entitled to activate plants.