New CIMTool builder needed to generated our latest IEC 61970-501 Ed 2.0 draft spec (alpha release)

[tviegut]

An initial alpha reference implementation of the IEC 61970-501 Ed 2.0 draft specification in CIMTool is needed. . Specifically, this issue is for tracking the development of the builder for generating the RDFS artifact as defined by 501 Ed 2.0. It is a work in progress and should be included in this release for those interested in alpha stage work on the format to be expressed within the standard. This builder should not contain profile constraints. Per 501 Ed 2.0 constraints will be defined with a separate artifact and expressed as SHACL rules for validation. That builder will be tracked by issue #53 .