Locking isnt working if the node is witihin the Viewport

[Chaosus]

Godot version:
e4ec59b

OS/device including version:
Win10

Issue description:

Steps to reproduce:

• Create a viewport (2D or 3D)
• Add node as a child
• Try use these buttons
  

[codecustard]

godot/editor/plugins/canvas_item_editor_plugin.cpp

Lines 4066 to 4075 in 9da24f7

	case LOCK_SELECTED: {
	undo_redo->create_action(TTR("Lock Selected"));
	List<Node *> selection = editor_selection->get_selected_node_list();
	for (List<Node *>::Element *E = selection.front(); E; E = E->next()) {
	CanvasItem *canvas_item = Object::cast_to<CanvasItem>(E->get());
	if (!canvas_item || !canvas_item->is_inside_tree())
	continue;
	if (canvas_item->get_viewport() != EditorNode::get_singleton()->get_scene_root())
	continue;

In line 4074, it appears to be deliberate. Removing this check in the lock/unlock switch cases resolves the issue.

[akien-mga]

As mentioned in #32446:

It was deliberately disabled by @reduz to fix some other bug #1383

[KoBeWi]

Still valid in 5bb7c7c

Seeing how this is intended and the locking would be useless (you can't move/select nodes inside Viewport anyways...), we should just disable the button if it's unavailable, to avoid confusion..

[Flavelius]

As my issue was closed, i'm pasting the link here (#44869), just to raise awareness that there are other more important and possibly linked issues, most importantly the missing scene handles and toolbar entries for controls.