Improve exported variable organization

[Duroxxigar]

Describe the project you are working on

Pretty much any game in Godot

Describe the problem or limitation you are having in your project

It is currently quite cumbersome to organize your exported variables. You need to have the script as a tool script, as well as override _get_property_list and then add some properties there. There is a lot of boilerplate with this. Especially when you need to also override _get and _set as well. And that is so that we can organize our variables with categories and collapsible sections like in this screenshot

Describe the feature / enhancement and how it helps to overcome the problem or limitation

I propose that we move this kind of functionality into the new annotations in GDScript 2.0. Not too sure how it works under the hood just yet however.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

I propose that the team looks into a more user friendly approach. With GDScript 2.0, we can use the annotations to handle this. This would be the proposed syntax.

@export(category=character, section=movement)
var move_speed

If this enhancement will not be used often, can it be worked around with a few lines of script?

It would be used quite frequently as exporting variables is a pretty common thing to do.

Is there a reason why this should be core and not an add-on in the asset library?

GDScript exports

[KoBeWi]

Duplicate of #3451 / #1255