Support "full debug mode" with metaschema-cli and Metaschema models at runtime

An an OSCAL developer who wants to do local and automated development and testing, I would like a variant of oscal-js that can perform "debug mode" that:

- Downloads and installs releases _or_ SNAPSHOT builds of `metaschema-cli`, _not_ `oscal-cli` to
- test new syntax additions and bug fixes to the metaschema-java project; and
- build the model and constraint files from particular commits for running integration tests and confirm features and bug fixes are implemented correctly

I am definitely excited to help with this effort, although it may be a separate repo and project (perhaps a metaschema-js). Let's discuss further and come up with a game plan if @wandmagic and/or other maintainers like this idea.

Start by reviewing oscal-js and the proposed separate metaschema-js project, then clarify the game plan with maintainers. The issue names metaschema-cli and metaschema-java as runtime dependencies and calls for release or SNAPSHOT downloads, commit-specific model and constraint builds, and integration-test validation; done requires an agreed implementation scope and working debug-mode workflow.

Written by the indexing model from the issue text.