Spatial transforms are already not sent to the VisualServer when physics interpolation is active, so there is actually no need for them to have NOTIFICATION_TRANSFORM_CHANGED called.
This PR manages the notify_transform state while respecting calls to set_notify_transform() in derived classes.

Notes

• Small optimization from [3.x] FTI - Fix 3D auto-resets #105463 I left for a separate PR because of the risk of regressions. So far it seems fine in testing.
• Has to manage a separate request to be notified by derived classes, it does this by maintaining two state bools and calculating the actual notify_transform state from these when required.
• Also applicable in 4.x.
• I'm not absolutely sure how much real world performance will be gained here, but needless notifications are always good to remove.