Change the default PropertyUsageFlags for var fields

[HenryWConklin]

PROPERTY_USAGE_NO_EDITOR still writes the property to files, which doesn't match the default property for vars in GDScript. PROPERTY_USAGE_NONE indicates that the property should not be saved or shown in the editor.

See https://docs.godotengine.org/en/stable/classes/class_@globalscope.html#class-globalscope-constant-property-usage-none

Fixes #463

[GodotRust]

API docs are being generated and will be shortly available at: https://godot-rust.github.io/docs/gdext/pr-464

[lilizoey]

as mentioned here i dont think this is correct.

[Bromeon]

Thanks! We should clarify whether Godot behaves according to specification, and if not, report it upstream. Let's continue discussion in #463 until this is clarified 🙂

[Bromeon]

Someone will need to double-check Godot's behavior upstream, I'm not sure if I get around it before the 4.2 release.
We should then act accordingly (if necessary at all).

Are there any disadvantages to using NONE instead of NO_EDITOR? Otherwise we could just merge, if it fixes the issue at hand.

[HenryWConklin]

If you look at the value on NO_EDITOR it's actually just an alias for STORAGE, meaning the field does get saved. From my understanding messing with this, that doesn't match the default behavior for vars in gdscript which don't include STORAGE. So if the goal is to match gdscript I think NONE is the right thing to use.

Gdscript vars do also include SCRIPT_VARIABLE, but from digging through the Godot code I can't figure out what it actually does. And it doesn't look like any native types' fields include it so I'm not sure if a gdext type should.

I see downsides for STORAGE, i.e. accidentally serializing some massive field. NONE does nothing except expose to gdscript as far as I can tell, so only downside would be if I'm wrong about what most users would expect.

[Bromeon]

Merging this for now, as it makes the behavior more consistent with GDScript. If Godot changes something, I'm open to adapt this again 🙂