* This notification makes node children management very inefficient.
* Replaced by a NOTIFICATION_CHILDREN_CHANGED (and children_changed signal).
* Changed Canvas code (and similar) to use the above signal, to perform more efficiently.
This PR breaks compatibility (although this notification was very rarely used, even within the engine), but provides an alternate way to do the same.
It is required for the changes in #75627 to be entirely effective.
- reduz
Note that I removed NOTIFICATION_MOVED_IN_PARENT, as keeping it, but making it just not work is worse in my opinion.
104392ef4e
When the layer of a CanvasLayer changes, the order of roots needs to be recalculated.
(cherry picked from commit 8d60e8b5d4120d9f9a4868bfb8f0059e733d6d5f)
