Intent of partition_API_adds_worker_to_shutdown_cache

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
  - service/ 3 tests
    
    matching/ 3 tests
    
    TestCancelOutstandingWorkerPolls/ 3 tests
    
    go.temporal.io/server/service/matching/TestCancelOutstandingWorkerPolls/adds_worker_to_shutdown_cache Inherited adds_worker_to_shutdown_cache
    
    go.temporal.io/server/service/matching/TestCancelOutstandingWorkerPolls/partition_API:_cancels_polls_and_populates_shutdown_cache Inherited partition_API:_cancels_polls_and_populates_shutdown_cache
    
    go.temporal.io/server/service/matching/TestCancelOutstandingWorkerPolls/partition_API_adds_worker_to_shutdown_cache Introduced here