SCE — Not enough need for vocabulary mechanisms in SCE

As part of finalizing an minimum viable product for SCE, remove the vocabulary mechanism. There has been much discussion about the topic and the necessity for the capability has been questioned.
In any case, the current mechanism doesn't work, especially which the proposed change to Semantic Reference.
We may need to include some sort of extendible enumeration capability at some point. This will be handled in conjunction with review of BKPMN, PPMN, PMN, and SDMN enumeration requirements.