Add a prefetch option to Waltz client

[whynick1]

Based on PerformanceCli test-consumers performance test, we believe most of the latency in inter-region performance tests are coming from the network hop between regions. The idea is to have the Waltz client add a shouldPrefetch function to the Waltz client requests that will allow the Waltz client internals to evaluate whether a record should be fetched immediately, rather than waiting for the application to call getTransactionData(). Then, when the application does call getTransactionData(), the request is short circuited, and the cached result is returned.

[whynick1]

shouldPrefetch should probably look something like:

boolean shouldPrefetch(RecordHeader);