Migrations: Log more info

[bricelam]

We should log more in Migraitons:

• What database we're targeting (verbose)

  Target database is: 'ConsoleApplication1.Context' (DataSource: (localdb)\mssqllocaldb, Provider: System.Data.SqlClient, Origin: Convention).

• Success messages

• What namespace is used for a migration (verbose)

• Where a migration is scaffolded (verbose)

• If data loss was scaffolded (warning)

[bricelam]

We should also log information during Add-Migration educating users about Remove-Migration