Bug or OOO: define variable attributes not working properly, or not implemented, when VLM is present (i.e., define_variable_ccode)

**Bug or OOO for the core engine v1.0: define variable attributes not working or not implemented for VLM (Value Level Metadata).**

At least define_variable_ccode is returning null when there is VLM defined. It means that apparently it disregards any VLM defined.

See example with draft rule CG0999 running as a local rule, using the released DatasetJSON v1.1 example on git: https://github.com/cdisc-org/DataExchange-DatasetJson/tree/master/examples/sdtm

Note:
I am testing with the core engine v0.14.1 on a linux machine.