Seven controlpanel overview and schema driven control panels

[ksuess]

parent issue: controlpanels: #6657

[ksuess]

The icons will be added later. I'd rather tackle more urgent matters.

[ksuess]

I'll pause here and continue when the widgets are ready.

[davisagli]

This might be too ambitious an idea to bring up, and I'm not sure how to implement it, but it could be nice if it was possible to search the control panel to find a setting (similar to System Settings in macOS).