Finds an existing Amazon SNS topic by iterating all SNS topics until a match is found.
The ListTopics method is used to fetch upto 100 SNS topics at a time until a SNS topic
with an TopicArn that matches
topicName is found.
public virtual Topic FindTopic( String topicName )
The name of the topic find
Supported in: 4.5, 4.0, 3.5