Added retries to avoid not enough replicas Exception

We encountered Exceptions stating that there would not be enough replicas available to fullfill the current request. Therefore i added a new RetryPolicy (PeakNetwork) which allows to retry those requests, which helped. Btw.: the datastax code mentions that this would not make sense as the retry would never succeed. However, our experience tells us differently, so i suppose we encounter a specific case not happening too often and i therefore sticked with the defaultpolicy to be the default in Presto.