GDExtension binary compatibility broken for _get_configuration_warnings()

[dsnopek]

Tested versions

• 4.3.dev [a9bb850]

System information

Ubuntu 22.04

Issue description

PR #68420 changed the return value for _get_configuration_warnings() from PackedStringArray to Array.

This breaks binary compatibility for GDExtension, which means that any GDExtension that implemented _get_configuration_warnings() would likely segfault if used with Godot master presently.

Suggestions from @akien-mga on RocketChat:

I think it might be best to revert the signature back and find a different way to handle property warnings. Could be a new virtual method, either for both node and property (deprecating the old one) or one only for property warnings.

Steps to reproduce

• Install a GDExtension which implements _get_configuration_warnings() (for example, Terrain3D)
• In the editor, add a Node that implements _get_configuration_warnings() a the scene (for example Terrain3D)
• Crash!

Minimal reproduction project (MRP)

Try the sample in the Terrain3D extension

[Mickeon]

Personal opinion is to bring back the original method as the one being exposed, whose result merges with a new "_get_configuration_warnings... whatever name is chosen" used exclusively with arrays of dictionaries.

[Mickeon]

Okay, I'm convinced. I hope whoever is at the helm to change this takes this these opinionated changes in mind:

• Bring back _get_configuration_warnings the way it was with PackedStringArray;
• Replace currently breaking method with an internal _get_configuration_warnings_dict. Do not expose it yet until further changes;
• Delegate configuration warnings to Object itself in some way;
  • See also Add a configuration warning system for Resources godot-proposals#9098
• Allow associating configuration warnings to properties in a more dynamic way.
  • I'm imagining, right off the bat, associating a property to a Callable. Something akin to update_configuration_warnings can then be called when a property changes, passing the property name, and... I think you get the gist.

[akien-mga]

I'd opt for reverting #68420 for now to fix the compat breakage, and then have @RedMser redo the PR with the suggested changes to avoid breaking the compatibility. Note that you can use git cherry-pick on the original commit to get it re-committed after the revert, then modify it.