Fix missing tooltips on "Advanced Import Settings for Scene" window

In Godot, it's possible to customize how the engine imports 3D resource,
by either clicking "Advanced..." button on Import Dock or double
clicking the resource on FileSystem Dock. Doing so will open the
Advanced Import Settings window, where user could inspect the 3D resource
in a viewport, with the scene tree on the left and an inspector panel
akin to the Import dock on the left. It contains the same settings from
the Import dock, with some advanced additions.

This commit fixes a regression since 4.2 where settings in the inspector
panel on the right part of the window does not contain the same tooltips
as its Import Dock counterpart (which were retrieved from the XML class
reference).

editor/import/3d/scene_import_settings.cpp

@@ -1891,6 +1891,9 @@ SceneImportSettingsDialog::SceneImportSettingsDialog() {
 	inspector = memnew(EditorInspector);
 	inspector->set_custom_minimum_size(Size2(300 * EDSCALE, 0));
 	inspector->connect(SNAME("property_edited"), callable_mp(this, &SceneImportSettingsDialog::_inspector_property_edited));
+	// Display the same tooltips as in the Import dock.
+	inspector->set_object_class(ResourceImporterScene::get_class_static());
+	inspector->set_use_doc_hints(true);
 
 	property_split->add_child(inspector);