Behavior of NewBinding and ExistingBinding are different inside Shot track

When using NewBinding, the bind does not work properly with the level sequence specified by ShotTrack.

The cause is that Guid of ExistingBindingID will be empty when passing through ActorPicked in ActorPickerTrackEditor.cpp. Because of this, the space of ConstraintBindingID set by F3DAttachTrackEditor :: AddKeyInternal becomes Root.

This issue is fixed by changing processing in AddKeyInternal as follows.

// ConstraintBindingID = FMovieSceneObjectBindingID(ParentActorId, GetSequencer()->GetFocusedTemplateID());
ConstraintBindingID = FMovieSceneObjectBindingID(ParentActorId, GetSequencer()->GetFocusedTemplateID(), EMovieSceneObjectBindingSpace::Local);

1. create new level sequencer
2. Register cone, cylinder with spawnable from mode panel
3. Attach cone to cylinder using NewBinding
4. create another level sequencer
5. Register the level sequencer created in 5, 1 with shot to 4

result : failed to attach in shot track