The getJSONuiLabel javascript function is no longer working

While working on some Ajax stuff I found that the getJSONuiLabel javascript function (and I guess getJSONuiLabels) is no longer working, and that's for a while. It's easy testable by looking at the "Field8: Javascript event" at https://demo-stable.ofbiz.apache.org/example/control/FormWidgetExamples, trunk demo is same.

This means that no errors is reported in UI because getJSONuiLabel/s are used by all error report tools, for instance the 50 showErrorAlert calls.

R15 and R14 have the same issue, R13 can't be tested (no example component) so it's indeed a while this issue exists.