Intent of When_ChildWorkflowExecutionCanceledEvent_added_it_will_be_placed_in_MemBuffer, When_ChildWorkflowExecutionCanceledEvent_added_it_will_be_placed_in_MemBuffer

All 3 exact tests in this concept. Every test is marked by where it enters the hierarchy.

go.temporal.io/ 3 tests
- server/ 3 tests
  - service/ 3 tests
    
    history/ 3 tests
    
    historybuilder/ 3 tests
    
    TestHistoryBuilder_AddDifferentEvents/ 1 test
    
    go.temporal.io/server/service/history/historybuilder/TestHistoryBuilder_AddDifferentEvents/When_ChildWorkflowExecutionCanceledEvent_added_it_will_be_placed_in_MemBuffer Introduced here
    
    TestHistoryBuilder_AddDifferentEvents_WorkflowFinishEvents/ 1 test
    
    go.temporal.io/server/service/history/historybuilder/TestHistoryBuilder_AddDifferentEvents_WorkflowFinishEvents/When_ChildWorkflowExecutionCanceledEvent_added_it_will_be_placed_in_MemBuffer Introduced here
    
    TestHistoryBuilder_FlushBufferToCurrentBatch_WiringEvents/ 1 test
    
    go.temporal.io/server/service/history/historybuilder/TestHistoryBuilder_FlushBufferToCurrentBatch_WiringEvents/for_every_Child_Workflow_event_should_point_to_its_causal_event Inherited for_every_Child_Workflow_event_should_point_to_its_causal_event