Intent of Adding_buffered_event_will_set_event_Id_to_common.BufferedEventID, When_WorkflowExecutionCancelRequestedEvent_added_it_will_be_placed_in_memBuffer, +1

All 4 exact tests in this concept. Every test is marked by where it enters the hierarchy.

go.temporal.io/ 4 tests
- server/ 4 tests
  - service/ 4 tests
    
    history/ 4 tests
    
    TestEngine2Suite/ 1 test
    
    go.temporal.io/server/service/history/TestEngine2Suite/TestRequestCancelWorkflowExecution_Running Inherited mutable_state_impl.go ×6
    
    historybuilder/ 3 tests
    
    TestHistoryBuilder_AddDifferentEvents/ 1 test
    
    go.temporal.io/server/service/history/historybuilder/TestHistoryBuilder_AddDifferentEvents/When_WorkflowExecutionCancelRequestedEvent_added_it_will_be_placed_in_memBuffer Introduced here
    
    TestHistoryBuilder_AddDifferentEvents_AssignmentEventId/ 1 test
    
    go.temporal.io/server/service/history/historybuilder/TestHistoryBuilder_AddDifferentEvents_AssignmentEventId/Adding_buffered_event_will_set_event_Id_to_common.BufferedEventID Introduced here
    
    TestHistoryBuilder_AddDifferentEvents_WorkflowFinishEvents/ 1 test
    
    go.temporal.io/server/service/history/historybuilder/TestHistoryBuilder_AddDifferentEvents_WorkflowFinishEvents/When_WorkflowExecutionCancelRequestedEvent_added_it_will_be_placed_in_memBuffer Introduced here