Intent of when_there_is_an_event_in_memBuffer_HasBufferEvents_should_be_true

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
    
    TestTimerQueueActiveTaskExecutorSuite/ 3 tests
    
    go.temporal.io/server/service/history/TestTimerQueueActiveTaskExecutorSuite/TestProcessActivityTimeout_NoRetryPolicy_Fire Inherited TestProcessActivityTimeout_NoRetryPolicy_Fire
    
    go.temporal.io/server/service/history/TestTimerQueueActiveTaskExecutorSuite/TestProcessActivityTimeout_RetryPolicy_Fire Inherited TestProcessActivityTimeout_RetryPolicy_Fire
    
    go.temporal.io/server/service/history/TestTimerQueueActiveTaskExecutorSuite/TestProcessActivityTimeout_RetryPolicy_RetryTimeout Inherited TestProcessActivityTimeout_RetryPolicy_RetryTimeout
    
    historybuilder/ 1 test
    
    TestHistoryBuilder_HasBufferEvents/ 1 test
    
    go.temporal.io/server/service/history/historybuilder/TestHistoryBuilder_HasBufferEvents/when_there_is_an_event_in_memBuffer_HasBufferEvents_should_be_true Introduced here