stop trying to detect move from another environment

- this state is the same as after an susbscribers-reset call.  causes us to delete all messages after subscribers-reset.  too dangerous to risk.
add option to use a persistent connection
update HubLifeSupport to use persistent connection for heartbeat
feature flags for persistent connection and elevated thread level
use "with no(lock)" hint when collecting stats
Merge branch '75561-dedicated-sql-conn-for-life-support'