Intent of scheduled-timedout

All 3 exact tests in this concept. Every test is marked by where it enters the hierarchy.

go.temporal.io/ 3 tests
- server/ 3 tests
  - components/ 3 tests
    
    nexusoperations/ 3 tests
    
    TestCompleteExternally/ 3 tests
    
    go.temporal.io/server/components/nexusoperations/TestCompleteExternally/backing_off-timedout Inherited backing_off-timedout
    
    go.temporal.io/server/components/nexusoperations/TestCompleteExternally/scheduled-timedout Introduced here
    
    go.temporal.io/server/components/nexusoperations/TestCompleteExternally/started-timedout Inherited started-timedout