Intent of TestLoadAndSortActivityTimers_One_Scheduled_Started_WithHeartbeatTimeout

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
    
    workflow/ 4 tests
    
    TestTimerSequenceSuite/ 4 tests
    
    go.temporal.io/server/service/history/workflow/TestTimerSequenceSuite/TestCreateNextActivityTimer_HeartbeatTimer_AfterWorkflowExpiry Inherited TestCreateNextActivityTimer_HeartbeatTimer_AfterWorkflowExpiry
    
    go.temporal.io/server/service/history/workflow/TestTimerSequenceSuite/TestCreateNextActivityTimer_HeartbeatTimer_BeforeWorkflowExpiry Inherited TestCreateNextActivityTimer_HeartbeatTimer_NoWorkflowExpiry, TestCreateNextActivityTimer_HeartbeatTimer_BeforeWorkflowExpiry
    
    go.temporal.io/server/service/history/workflow/TestTimerSequenceSuite/TestCreateNextActivityTimer_HeartbeatTimer_NoWorkflowExpiry Inherited TestCreateNextActivityTimer_HeartbeatTimer_NoWorkflowExpiry, TestCreateNextActivityTimer_HeartbeatTimer_BeforeWorkflowExpiry
    
    go.temporal.io/server/service/history/workflow/TestTimerSequenceSuite/TestLoadAndSortActivityTimers_One_Scheduled_Started_WithHeartbeatTimeout Introduced here