[Feature Request] Souls of Enemies/NPCs

I recall there being an old branch featuring randomized Souls for NPCs where they would not spawn until you found their corresponding soul. I think it's like the last major feature missing that other randomizers have is the souls of NPCs and for Enemies (except Enemy Drops I guess). I do recall it being pretty accurate before with a few logic issues, I don't know if backend changes have affected this.

In terms of Enemy Souls, I recall N64 having options of Enemy Souls (e.g. Souls of Guays) or Location Based Souls (e.g. Souls of Enemies in Lake Hylia), It also could be done similar to how 2Ship works where they are invulnerable until you find the soul, or just are despawned until you find them like the other randomizers.

Start by locating the old branch mentioned in the issue and comparing it with current backend behavior. Review the N64 and 2Ship approaches described, then clarify which soul model and spawn or invulnerability behavior should be implemented; done means an agreed design is implemented for NPCs and enemies with working randomizer logic.

Written by the indexing model from the issue text.