[feature] Add an query option orderedPreferredReplicas to control servers will be hit

[wirybeaver]

Context: All Uber's stateless production service has nodes in a canary zone. The release will be rolled to canary zone at first. In order to reduce the blast radius when the release is baked in the canary zone, we wanted to eliminate the canary traffic into a certain replicas at the basis of best of effort. If none of replica groups which are specified in the query option is online, choose the available replicas to guarantee the query success rate. Otherwise, select the first available replica from the specified list orderedPreferredReplicas. We will focus on tables enabling the replica group segment assignment strategy at the beginning.

Haven't look at the existing implementation to see whether there's any hard blockers but should tweak this api link

More design details will be posted after ramping up the company's OKR this year. Raise this discussion to kick off the discussion and to see whether there's any strong objection to this query option based routing strategy