Adds metadata tags to an Amazon RDS resource. These tags can also be used with cost allocation reporting to track cost associated with Amazon RDS resources, or used in a Condition statement in an IAM policy for Amazon RDS.
/// DBClusterIdentifier does not refer to an existing DB cluster.
///
/// DBInstanceIdentifier does not refer to an existing DB instance.
///
/// DBSnapshotIdentifier does not refer to an existing DB snapshot.
///