Backup and recovery: 8 API change passages

Added the restoreArtifactsBulkRequestStatus enumeration type. Added the driveRestoreArtifactsBulkAdditionRequest resource and associated methods. Added the mailboxRestoreArtifactsBulkAdditionRequests relationship to the exchangeRestoreSession resource. Added the mailboxRestoreArtifactsBulkAdditionRequest resource and associated methods. Added the driveRestoreArtifactsBulkAdditionRequests relationship to the oneDriveForBusinessRestoreSession resource. Added the restoreArtifactsBulkRequestBase resource. Added the siteRestoreArtifactsBulkAdditionRequests relationship to the sharePointRestoreSession resource. Added the siteRestoreArtifactsBulkAdditionRequest resource and associated methods.