Intent of StartToClose_set_but_not_ScheduleToClose_-_fills_from_runTimeout

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
  - chasm/ 1 test
    
    lib/ 1 test
    
    activity/ 1 test
    
    TestModifiedActivityTimeouts/ 1 test
    
    go.temporal.io/server/chasm/lib/activity/TestModifiedActivityTimeouts/StartToClose_set_but_not_ScheduleToClose_-_fills_from_runTimeout Introduced here