Add support for FTS/PolyBase/ML etc. to `sqlcmd create`

We might need a workload and features concept for sqlcmd.  Create me a TDS endpoint for this type of workload (which bundles a bunch of features), and/or Create me a TDS endpoint with these specific features.

`sqlcmd create mssql --feature polybase --feature fts`
`sqlcmd create mssql --workload saas-isv`