Add SolarHomeSystemSeeder

[dmohns]

Brief summary of the change made

This adds data seeding for SolarHomeSystem. So far, we are only creating un-sold devices which can be sold in the Demo application.

Are there any other side effects of this change that we should be aware of?

No

Describe how you tested your changes?

docker compose up

Pull Request checklist

Please confirm you have completed any of the necessary steps below.

• Meaningful Pull Request title and description
• Changes tested as described above
• Added appropriate documentation for the change.
• Created GitHub issues for any relevant followup/future enhancements if appropriate.