Set hard thread affinity for each zone

Set hard thread affinity for each zone

After switching to per-thread resources in the zonemgr, the performance
was decreased because the memory context, zonetask and loadtask was
picked from the pool at random.

Pin the zone to single threadid (.tid) and align the memory context,
zonetask and loadtask to be the same, this sets the hard affinity of the
zone to the netmgr thread.