ExecutableNodeUI : Fix UI for individually promoted pre/post tasks.
ExecutableNodeUI : Fix UI for individually promoted pre/post tasks.

We need to register metadata for the array children so that they can carry it with them if they are promoted on their own.

GafferHQ/gaffer,boberfly/gaffer,ImageEngine/gaffer,lucienfostier/gaffer,andrewkaufman/gaffer,appleseedhq/gaffer,hradec/gaffer,boberfly/gaffer,chippey/gaffer,johnhaddon/gaffer,johnhaddon/gaffer,ivanimanishi/gaffer,boberfly/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,GafferHQ/gaffer,lucienfostier/gaffer,boberfly/gaffer,chippey/gaffer,ivanimanishi/gaffer,johnhaddon/gaffer,ImageEngine/gaffer,GafferHQ/gaffer,lucienfostier/gaffer,chippey/gaffer,ImageEngine/gaffer,lucienfostier/gaffer,ImageEngine/gaffer,andrewkaufman/gaffer,ivanimanishi/gaffer,ivanimanishi/gaffer,hradec/gaffer,appleseedhq/gaffer,andrewkaufman/gaffer,andrewkaufman/gaffer,hradec/gaffer,andrewkaufman/gaffer,hradec/gaffer,johnhaddon/gaffer,appleseedhq/gaffer,chippey/gaffer,GafferHQ/gaffer,appleseedhq/gaffer,hradec/gaffer