Intent of child_first_run_id_is_set

All 1 exact test in this concept. Every test is marked by where it enters the hierarchy.

go.temporal.io/ 1 test
- server/ 1 test
  - service/ 1 test
    
    history/ 1 test
    
    TestEngine2Suite/ 1 test
    
    TestRecordChildExecutionCompleted_ChildFirstRunId/ 1 test
    
    go.temporal.io/server/service/history/TestEngine2Suite/TestRecordChildExecutionCompleted_ChildFirstRunId/child_first_run_id_is_set Introduced here