Don’t know of anything exactly like you request. One problem is that folks tend to reassign a lot of the Key Commands. Lots of very useful functions don’t have default keys assigned to them. And lots of the default assigned keys might not be anything you specifically need. Yet those unneeded commands are using up lots of the good “easy to use keys” - so replace those with ones you like. Pretty much a moving target out in the wild.
But this will show you all your currently assigned key Commands.