
Changes to HRANDFIELD and ZRANDMEMBER: * Fix risk of OOM panic when client query a very big negative count (avoid allocating huge temporary buffer). * Fix uneven random distribution in HRANDFIELD with negative count (wasn't using dictGetFairRandomKey). * Add tests to check an even random distribution (HRANDFIELD, SRANDMEMBER, ZRANDMEMBER). Co-authored-by: Oran Agra <oran@redislabs.com>