C# [GlobalClass] Nodes and Resources named as same as builtin Godot classes won't show up in Editor's Node/Resource pickers even if there's no logical collision

Even if there's no logical collision (builtin class is not a Node/Resource) and even if declared in namespaces. No errors, successfully registering in godot_global_class_cache.cfg, no problems with attaching script by hand.

### Steps to reproduce

Name [GlobalClass] (derived from Node or Resource ofc) "SceneState" for example (then build). It will not be shown in "Add child..." or "Create new..." dialogs (although it doesn't conflict with any other Node/Resource and can be attached by hand in scene/project. Also there's no warning even if real name collision exists (name it "Node3D").

Reproduce with a C# [GlobalClass] derived from Node or Resource, using names such as SceneState and Node3D, then inspect global class cache registration and the Editor's Add Child and Create New pickers. Done means valid classes appear in the appropriate picker, while genuine name collisions produce a warning.

Written by the indexing model from the issue text.