Use ignore/illegal bins to filter instr group cg
Created by: silabs-robin
This is an attempt to simplify the filtering of bins in the instruction group cg.
As far as I can see, tweaking the cfg will make covergroups appear/disappear in the coverage results. It should be the same as before except that the bins are shown prefixed "AUTO", unless if I have overlooked anything important (hence why I create this PR for review/discussion).
Continues from https://github.com/openhwgroup/core-v-verif/pull/592