Intent of TestGetActivityHeartbeatTimeout_WithoutHeartbeat_Started_Heartbeated, TestGetActivityHeartbeatTimeout_WithoutHeartbeat_Started_NoHeartbeat

All 5 exact tests in this concept. Every test is marked by where it enters the hierarchy.

go.temporal.io/ 5 tests
- server/ 5 tests
  - service/ 5 tests
    
    history/ 5 tests
    
    workflow/ 5 tests
    
    TestTimerSequenceSuite/ 5 tests
    
    go.temporal.io/server/service/history/workflow/TestTimerSequenceSuite/TestGetActivityHeartbeatTimeout_WithoutHeartbeat_Started_Heartbeated Introduced here
    
    go.temporal.io/server/service/history/workflow/TestTimerSequenceSuite/TestGetActivityHeartbeatTimeout_WithoutHeartbeat_Started_NoHeartbeat Introduced here
    
    go.temporal.io/server/service/history/workflow/TestTimerSequenceSuite/TestLoadAndSortActivityTimers_Multiple Inherited TestLoadAndSortActivityTimers_Multiple
    
    go.temporal.io/server/service/history/workflow/TestTimerSequenceSuite/TestLoadAndSortActivityTimers_One_Scheduled_Started_Heartbeated_WithoutHeartbeatTimeout Inherited TestLoadAndSortActivityTimers_One_Scheduled_Started_WithoutHeartbeatTimeout, TestLoadAndSortActivityTimers_One_Scheduled_Started_Heartbeated_WithoutHeartbeatTimeout
    
    go.temporal.io/server/service/history/workflow/TestTimerSequenceSuite/TestLoadAndSortActivityTimers_One_Scheduled_Started_WithoutHeartbeatTimeout Inherited TestLoadAndSortActivityTimers_One_Scheduled_Started_WithoutHeartbeatTimeout, TestLoadAndSortActivityTimers_One_Scheduled_Started_Heartbeated_WithoutHeartbeatTimeout