Some way to add functions to g_PostSimulationQueue

[Bo98]

If we change anything to do with physics in a physics callback, the engine rightly prints errors: "changing collision rules within a callback is likely to cause crashes!".

What entities in the engine do in callbacks such as VPhysicsCollision (ENT:PhysicsCollide), is that they queue changes to collision rules into g_PostSimulationQueue, either directly or through helper functions like PhysCallbackDamage(...). Right now if we want to, for example, remove an entity on impact via ENT:PhysicsCollide, we have to use a timer - which is horrible and delays everything by a frame.

Additionally, a binding to PhysIsInCallback() would be nice to go in hand with this.

[Kefta]

Please consider this 🙏 many addons have had to implement timers everywhere to do the operations needed post-collision to avoid the console message. This would be extremely useful.