[UX] Add charts to the dashboard

in the dashboard rather than textual information, provide (where you can) graphical information in the form of charts (for example system updates or statistics like grav admin panel do) to provide a quick and intuitive "global" information

This issue was spun off from a comment by @fivepoints79 in https://github.com/backdrop/backdrop-issues/issues/495#issuecomment-4614...