Pause/unpause Actors and Entities feature

[eonarheim]

Context

Sometimes it is useful to pause the update and/or draw of an actor without removing it from the scene to save on performance.

One examples might be NPCs that exist offscreen and don't need to run their logic until they are onscreen.

Proposal

Add a new method (open to different names) .pause() or .unpause() that should leverage the entity.active property to suspend updates and/or drawing.

.kill() should be updated to use a different property internally.

[github-actions]

This issue hasn't had any recent activity lately and is being marked as stale automatically.