Need ability to debug into base plugin from sub plugin

[live1206]

Clear and concise description of the problem

We are starting to implement Azure plugin inheriting SCM ClientModelPlugin.
Once we hit an issue, we would need the ability to set a break point in the base plugin and debug into it.

Checklist

• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[JoshLove-msft]

I've submitted a PR that adds a launch settings profile to make it easy to debug, but it should be possible to step into the MGC code. Just make sure you don't have "Just My Code" selected in your VS settings.