The former implementation had 5 threads permanently spinning fast
(10ms sleep) while waiting for a REST connection to process.
This causes higher load in general and it breaks systems where
"Turn on PowerShell Script Block Logging policy" is enabled,
because then each PS statement including Start-Sleep is logged -
resulting in 500 event log entries per second. It's a suggested
setting in some hardening guidelines.
We can easily replace the Queue with a BlockingCollection backed
by a ConcurrentQueue, which has the built-in feature to sleep until
there are new items. Now the REST API threads consumes zero CPU time
while waiting.
