Compatibility with FreeCam mods

I am developer of one of FreeCam mods. We know that typical FreeCam mod creates fake player entity in spectator gamemode. And baritone `ComeCommand` works fine with it by using `BaritonePlayerContext.viewerPos` method, which returns fake entity position in this case.

However my FreeCam mod uses 3rd person view, and moves ingame Camera object without creating any fake entities. This is why current baritone approach doesn't work with my FreeCam. Can we make improvement to support both cases?

The simplest way to achieve this would be to use Camera position, not entity position. Such change will affect `ComeCommand` and `SelCommand`. If player is in first person, camera position is one block above old method. This is not good if baritone users get used to old behavior. I am in doubts. I can definitely make mixin into baritone from my mods, but maybe you have smarter ideas.