Workflow changes not being stored in tracking tables correctly


To align with the functionality of the SQL Server provider and make sure that change stored to the tracking store can be re-applied during tracking query, the way changes are stored in ADDED_ACTIVITY and REMOVED_ACTIVITY must be changed. Currently, only the XML of the activity being added or deleted is stored in the table, but instead, the XML of the AddedActivityAction or RemovedActivityAction should be stored there. Also, for child entries, the ORDER field should be NULL rather than -1 for consistency.