Intent of TestLoadAndSortActivityTimers_One_Scheduled_Started_Heartbeated_WithHeartbeatTimeout

All 1 exact test in this concept. Every test is marked by where it enters the hierarchy.

go.temporal.io/ 1 test
- server/ 1 test
  - service/ 1 test
    
    history/ 1 test
    
    workflow/ 1 test
    
    TestTimerSequenceSuite/ 1 test
    
    go.temporal.io/server/service/history/workflow/TestTimerSequenceSuite/TestLoadAndSortActivityTimers_One_Scheduled_Started_Heartbeated_WithHeartbeatTimeout Introduced here