Is your feature request related to a problem?

This is the first step with #1399, to add support for KerML

Describe the solution you'd like

The SysML v2 Pilot Implementation uses Xtext to define the KerML language, since SysML is no longer built on top of UML. In Python, we have TextX, which can use Xtext like definitions, with some changes that are documented here: https://textx.github.io/textX/3.1/about/comparison/#difference-to-xtext-grammar-language. Xtext is a more traditional grammar parser and TextX uses a PEG parser.

One of the tricky things that we need to figure out is that the Xtext definitions use ECore, and import an EPackage of the SysML metamodel schema to define KerML.

There is a JSON version of that schema definition here: https://www.omg.org/spec/SysML/20230201/SysML.json. I think that using the JSON as its own metamodel that the TextX metamodel can reference would be ideal.