Speculative query retries
Speculative retries to smooth out response times. Especially important with TokenAware routing and CL.ONE, because we then don't get to take advantage of the server-side speculative retries.
Note: This could be a very large effort because it will require a host latency-aware component, which is not presently implemented for this driver.
Changes based on PR are complete and PR is merged moving this to done.