Investigate latency tracking

[tezc]

Introduced by redis/redis#9462

In RM_Call(), we hit this line: https://github.com/redis/redis/blob/bed6d759bcb1ddcdab76da1b46a120e2e610036b/src/server.c#L3423

• Module clients are not real, so probably this is not necessary for module clients. (Introducing performance cost).
• Maybe there must be a way to associate latency info (raft + redis latency together) with real clients. Otherwise, we need to document this as an unsupported feature.