00a6fda7b9
Secondary tracing sessions used to compute the execution time from the point of their `begin()`-ning, not the parent session's `begin()`. As a result, replica reported a slow query if it exceeded the entire threshold *on that replica* too. This change augments `trace_info` with the TS of parent's session starting point, to be used as a reference on replicas. Fixes #9403 Closes #10005