Enable "Copy As New Driver" for String properties

Right-clicking on a String property (such as a String field of an add-on) doesn't show a "Copy As New Driver" pop-up menu, unlike for numerical values or booleans. Which means we cannot link such properties to Geometry Nodes using strings (unless there is a way I don't know about).

For example, we cannot use a Driver to drive the name of the Store Named Attribute node.