Add dry run capability to generate SQL for docs and other artifacts

[shah]

To aid in documentation and related comprehension tasks, add a dry run option to IngestEngine so that it can generate SQL but not execute it.

• [ ] output of a dry run should be Markdown
• [ ] output of a dry run could be Deno-based Jupyter Notebook
• [ ] output of a dry run could be custom Deno code which would be specific to the workflow and SQL and then executed in memory or saved to disk for later execution (almost like a compile option). The benefit of this approach is that it would allow run Deno test, lint, doc, coverage, etc. on the generated code.

[shah]

OBE, no longer required.