PowerShell cmdlet change for Standard DR improvement

1. The Start-AzureSqlDatabaseCopy cmdlet now accepts a new switch parameter “-OfflineSecondary” to indicate whether this is to start a passive CC or an active CC.
2. The object type Microsoft.WindowsAzure.Commands.SqlDatabase.Model.DatabaseCopy has two new fields: IsOfflineSecondary and IsTerminationAllowed. This is the object type returned by cmdlets such as Get-AzureSqlDatabaseCopy, Start-AzureSqlDatabaseCopy, etc.
3. Update AzureSqlContinuousDatabaseCopyCertTests to test the changes.