JavaScript CIM export

[derrickoswald]

An export function exists in the CIMReader, but only from Scala classes. This capability should be extended to the generated JavaScript classes. This will require:

• adding export code via the CIMTool JavaScript generator
• this may require converting the existing JavaScript CIM class objects into ES6 classes, or just providing a wrapper for the current "bag-o-properties" JavaScript objects
• add a supervisory function that adds CIM XML headers and assembles the individual CIM elements into an in-memory file
• consideration should be given to also exporting JSON as advocated by Alan McMorran if a specification is publicly available

[derrickoswald]

Implemented as a bag-o-properties wrapper. Exporting JSON is only performed if the class is not recognized.