Creates a topic to which notifications can be published. Users can create at most 100,000 standard topics (at most 1,000 FIFO topics). For more information, see <a href="https://docs.aws.amazon.com/sns/latest/dg/sns-create-topic.html">Creating an Amazon SNS topic</a> in the <i>Amazon SNS Developer Guide</i>. This action is idempotent, so if the requester already owns a topic with the specified name, that topic's ARN is returned without creating a new topic.