WIP: Add entity API integration for field discovery

I'd rather not segregate this into a different method for Developer Experience. After all this is an optional feature.

I have to admit that I was tempted to go this route too, but I backed because it seemed cumbersome to implement. I imagine devs having to match keys in both functions and having to implement 2 different methods and I see potential bugs all over the place.

Do you have strong feelings about this? I can still be talked into it :stuck_out_tongue: