The collision code takes an AABB and generates a cuboid of checks rather
than a cylinder, so at high velocity this can generate a lot of chunk checks.
Treat an unloaded chunk as a collision for entities, and also for players if
the "prevent moving into unloaded chunks" setting is enabled.
If that setting is not enabled, collisions will be ignored for players, since
movement will load only the chunk the player enters anyways and avoids loading
massive amounts of surrounding chunks due to large AABB lookups.
Fixes#3321
