Fixing Stress SimpleEchoHub latency tests
-Using one transport instance per connection
-One roundtrip at a time over a connection
-Microseconds precision
-Adding WebSockets and SSE external variants
Fixing Stress SimpleEchoHub latency tests; PR feedback
-use async/await for callback completions
-use proxy handler generic arg for long cast
-changing back to ms units
Fixing Stress SimpleEchoHub latency tests; PR feedback
-using UTCNow