Signal to track the exported variable

[JekSun97]

I'm working on a project where there are characters, and using an exported variable of the enum type, I want to change the armor/clothing on the characters from the editor, add a signal to change the exported variables.
func _change_var_export ( VarName: String, NewValue: Variant)

Please also add this for version 3.6

[AThousandShips]

Duplicate of #4868