ControlObjects for BocEnumValue and BocReferenceValue do not use the always-available text representation of the option entries

BocEnumValue and BocReferenceValue can always supply a sensible text representation for the individual options, in particular, the null-item. Given that the control objects do not evaluate diagnostic metadata when building the options, this information is not properly transported to the web test.

Note that BocEnumValue already uses diagnostic metadata during rendering but not in the control objects while BocReferenceValue does not use diagnostic metadata for the options at all.