Consider adding handling to ActorSheetV2 for Actor#overrides

[JPMeehan]

The Actor#overrides property is intended to track which fields have been altered by an AE and should not be passed back as part of a form submission update. I think there's two options for implementing this.

1. Parity with ActorSheet: Strip overrides from the form submission handler
2. ALSO disable any input fields with a name property in the keys of overrides

It's possible that this second feature would conflict with other rendering frameworks, since it's a DOM modification. Would probably be good to survey devs in the AppV2 thread regarding this.

[JPMeehan]

@aaclayton I take it that this is not getting into v12 at all, then?

[aaclayton]

It's not going to make it. Will have to wait for V13 when we actually start converting actor sheets to ApplicationV2. Systems which want to early-adopt are welcome to lift-and-shift this code themselves or devise an alternative approach for defining which fields should be editable.

[JPMeehan]

Okay. I got it working in Boilerplate so that at least will help anyone starting out on system development soon, same with DragDrop.