[Suggestion] Natural Mob Spawning Flag

### The Problem

I'd like to disable only the spawning of naturally spawning mobs in a given region.

### A Solution

Adding a new flag: "natural-mob-spawning".

Its function would only disable the spawning of natural mobs and allow other methods of summoning an entity (via commands, spawn eggs, spawners or others).

### Alternatives

_No response_

### Anything Else?

_No response_