Display multiplayer authority ID in remote debugger

[SaracenOne]

Adds the multiplayer_authority ID value to the remote node debugger.

[Calinou]

I suggest using PROPERTY_USAGE_READ_ONLY so that the property is visible, but can't be edited (unless it makes sense to be editable).

PS: Would this approach be useful to implement godotengine/godot-proposals#8091?

[SaracenOne]

So I actually did originally use read-only here (along with adding to the constant list), but I was bothered somewhat by the lack of the ability to selected read-only values for copy-pasting, but I think you're right that it would be better to add it and improve the interactions with read only properties.

Regarding that proposal, yeah, I agree that that is a problem, I think we do need a more general-purpose way to define properties which make sense to only show up in the remote debugger. I wonder what would be the best way to implement this.

[SaracenOne]

Okay, updated, it's now flagged appropriately as read-only.

[akien-mga]

Thanks!