Updated backup tasks to use new ambient environment settings
Added validation to checkdb task
Fixed issue in CopyDatabaseBackup with new model
Updated CreateWarehouseArtifacts
Made CreateWarehouseArtifactsTask special-purpose
Updated CreateWarehouseReportsTask
Updated DeleteOldWarehouseBackupsTask
Updated PurgePackageStatisticsTask
Updated ReplicatePackageStatisticsTask
Updated SynchronizePackageBackupsTask
Fixed issue with running Invoke-GalleryOperations with no arguments