Add queue_update() method to ReflectionProbe

[jtnicholl]

Add a queue_update method to ReflectionProbe, which forces the probe to update.
This new method is cleaner and more self-documenting than moving it a small amount, which is currently the way to force update a probe.
This is from #55929, I just split off this method from the rest of the PR and updated it for latest master.

[clayjohn]

As I commented in #55929 I do not think we should implement a half-solution. We either need to properly implement time slicing or we need wait until someone does. I'm happy to give you some pointers on where to make the relevant changes if you are interested

[jtnicholl]

To me this is just a better alternative to calling reflection_probe.translate(Vector3(0, 0.0001, 0)), which is something I do in one of my projects whenever a light is turned on or off. It's a bit of a hack, and it's confusing to someone who sees it and doesn't know why it's there unless an explanatory comment is included.
What you suggested about tying updates to nearby objects could be an alternative, but that might be less performant, and implementing it is beyond what I know how to do.

[Calinou]

Note that #97773 implements time slicing on top of ReflectionProbe.queue_update().