Add OnEditor<T>, remove impl<T> Export for Gd<T> and DynGd<T, D>

- Rearrange the code; move implementations for `OnEditor<Gd<T>>` and `OnEditor<DynGd<D, T>>` to their associated files (`gd.rs` and `dyn_gd.rs`).
- Inform user about available use cases for `OnEditor<T>` in associated docs
- Clean up the API – don't allow to create initialized `OnEditor<T>` value, delegate initialization to `init(...)` method, limit usage of `uninit` to Directly Exportable GodotTypes.

Author: Yarwin

godot-core/src/builtin/collections/array.rs

@@ -16,7 +16,7 @@ use crate::meta::{
     CowArg, FromGodot, GodotConvert, GodotFfiVariant, GodotType, ParamType, PropertyHintInfo,
     RefArg, ToGodot,
 };
-use crate::obj::{bounds, Bounds, Gd, GodotClass};
+use crate::obj::{bounds, Bounds, DynGd, Gd, GodotClass};
 use crate::registry::property::{Export, Var};
 use godot_ffi as sys;
 use sys::{ffi_methods, interface_fn, GodotFfi};
@@ -1114,6 +1114,21 @@ where
     }
 }
 
+impl<T: GodotClass, D> Export for Array<DynGd<T, D>>
+where
+    T: GodotClass + Bounds<Exportable = bounds::Yes>,
+    D: ?Sized + 'static,
+{
+    fn export_hint() -> PropertyHintInfo {
+        PropertyHintInfo::export_array_element::<DynGd<T, D>>()
+    }
+
+    #[doc(hidden)]
+    fn as_node_class() -> Option<ClassName> {
+        PropertyHintInfo::object_as_node_class::<T>()
+    }
+}
+
 impl<T: ArrayElement> Default for Array<T> {
     #[inline]
     fn default() -> Self {

godot-core/src/obj/dyn_gd.rs

@@ -495,7 +495,6 @@ where
     }
 }
 
-#[doc(hidden)]
 #[allow(clippy::derivable_impls)]
 impl<T, D> Default for OnEditor<DynGd<T, D>>
 where
@@ -506,6 +505,7 @@ where
         OnEditor::null()
     }
 }
+
 impl<T, D> Export for Option<DynGd<T, D>>
 where
     T: GodotClass + Bounds<Exportable = bounds::Yes>,
@@ -517,6 +517,46 @@ where
             ..PropertyHintInfo::export_gd::<T>()
         }
     }
+
+    fn as_node_class() -> Option<ClassName> {
+        PropertyHintInfo::object_as_node_class::<T>()
+    }
+}
+
+impl<T, D> GodotConvert for OnEditor<DynGd<T, D>>
+where
+    T: GodotClass,
+    D: ?Sized,
+{
+    type Via = Option<<DynGd<T, D> as GodotConvert>::Via>;
+}
+
+impl<T, D> Var for OnEditor<DynGd<T, D>>
+where
+    T: GodotClass,
+    D: ?Sized + 'static,
+{
+    fn get_property(&self) -> Self::Via {
+        OnEditor::<DynGd<T, D>>::get_property_inner(self)
+    }
+
+    fn set_property(&mut self, value: Self::Via) {
+        OnEditor::<DynGd<T, D>>::set_property_inner(self, value)
+    }
+}
+
+impl<T, D> Export for OnEditor<DynGd<T, D>>
+where
+    OnEditor<DynGd<T, D>>: Var,
+    T: GodotClass + Bounds<Exportable = bounds::Yes>,
+    D: ?Sized + 'static,
+{
+    fn export_hint() -> PropertyHintInfo {
+        PropertyHintInfo {
+            hint_string: get_dyn_property_hint_string::<D>(),
+            ..PropertyHintInfo::export_gd::<T>()
+        }
+    }
     fn as_node_class() -> Option<ClassName> {
         PropertyHintInfo::object_as_node_class::<T>()
     }

godot-core/src/obj/gd.rs

@@ -917,14 +917,49 @@ where
     }
 }
 
-#[doc(hidden)]
 #[allow(clippy::derivable_impls)]
 impl<T: GodotClass> Default for OnEditor<Gd<T>> {
     fn default() -> Self {
         OnEditor::null()
     }
 }
 
+impl<T: GodotClass> GodotConvert for OnEditor<Gd<T>>
+where
+    Option<<Gd<T> as GodotConvert>::Via>: GodotType,
+{
+    type Via = Option<<Gd<T> as GodotConvert>::Via>;
+}
+
+impl<T> Var for OnEditor<Gd<T>>
+where
+    T: GodotClass,
+    OnEditor<Gd<T>>: GodotConvert<Via = Option<<Gd<T> as GodotConvert>::Via>>,
+{
+    fn get_property(&self) -> Self::Via {
+        OnEditor::<Gd<T>>::get_property_inner(self)
+    }
+
+    fn set_property(&mut self, value: Self::Via) {
+        OnEditor::<Gd<T>>::set_property_inner(self, value)
+    }
+}
+
+impl<T> Export for OnEditor<Gd<T>>
+where
+    T: GodotClass + Bounds<Exportable = bounds::Yes>,
+    OnEditor<Gd<T>>: Var,
+{
+    fn export_hint() -> PropertyHintInfo {
+        PropertyHintInfo::export_gd::<T>()
+    }
+
+    #[doc(hidden)]
+    fn as_node_class() -> Option<ClassName> {
+        PropertyHintInfo::object_as_node_class::<T>()
+    }
+}
+
 impl<T: GodotClass> PartialEq for Gd<T> {
     /// ⚠️ Returns whether two `Gd` pointers point to the same object.
     ///