Expand functionality in the "SSCM" area

[ostojicb]

We could consider improving the area that's covered with SQL Server Configuration Manager, (as in https://github.com/microsoft/SQLServerPSModule/issues/4), e.g., add/remove startup parameters (like trace flags etc) and so on.

Alternatively, it could be useful to have a TF-specific cmdlet that executes TRACEON/TRACEOFF queries, and optionally apply the change for startup TF params