add HDR versions of Timer and Histogram metrics

based Coda Hale's Histogram metric on Gil Tene's HdrHistogram to get better accuracy of percentiles
(HdrTimer uses HdrHistogram internally)

initially use both new metrics in JournalReader/KafkaJournal
create benchmark-csv directory before trying to write to it
use persisted inputs to find a suitable input id for message metadata

due to a race condition during startup the inputs might not have been loaded yet, but if they are persisted we can use them anyway