Reinstate debug assertions

Created by: silabs-robin

This PR re-enables 40x' debug assertions, re-wiring some connections and re-writing some of the assertions.

It passes in both sim and formal (NB! Needs assumes to limit obi wait states). Though it is not fully 100% complete, most of it has been restored. This should be thoroughly reviewed, and I will try to assist in that. Don't hold back any criticism or questions. I already suspect that some changes are necessary, but I don't know what the right call is. @silabs-oysteink