Adding powermeter interface to DcSupplySimulator

[SebaLukas]

Describe your changes

see title

Issue ticket number and link

Missing powermeter interface in DcSupplySimulator

Checklist before requesting a review

• [x] I have performed a self-review of my code
• [ ] I have made corresponding changes to the documentation
• [x] I read the contribution documentation and made sure that my changes meet its requirements

[barsnick]

Oops, too late, already merged. 😁