Adds a callback that is run every time a global context option is changed. This refers to context options set in the Edit → Context Options window. The callback is not run when a context option value is modified by a node, such as the Edit Context Options LOP.
The callback is run whenever the value a context option changes, when a new context option is added, the UI description of a context option is changed, or when a context option is removed. In all cases, the name of the modified context option is passed as a string to the callback function.