Intent of canceled, scheduled-canceled

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
  - components/ 4 tests
    
    nexusoperations/ 4 tests
    
    TestCompleteExternally/ 3 tests
    
    go.temporal.io/server/components/nexusoperations/TestCompleteExternally/backing_off-canceled Inherited backing_off-canceled
    
    go.temporal.io/server/components/nexusoperations/TestCompleteExternally/scheduled-canceled Introduced here
    
    go.temporal.io/server/components/nexusoperations/TestCompleteExternally/started-canceled Inherited started-canceled
    
    TestCompleteFromAttempt/ 1 test
    
    go.temporal.io/server/components/nexusoperations/TestCompleteFromAttempt/canceled Introduced here