MB-30463: HashTableBench: Add 'Find' benchmark
MB-30463: HashTableBench: Add 'Find' benchmark

Add a new benchmark to the HashTableBench suite which measures the
time taken to find items in the HashTable.

Change-Id: I1809c6326e2c30e7d290ff7774709ce2e100af3f
Reviewed-on: http://review.couchbase.org/96844
Reviewed-by: Tim Bradgate <f1a26ee65f021cb7d82b83dfb09abf144d3eb64f@couchbase.com>
Reviewed-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@gmail.com>
Reviewed-by: Paolo Cocchi <9dd88c9f3e5cbab6e19a6c020f107e0c648ac956@couchbase.com>
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>

daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine