Intent of TestReadiness_Ready

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
  - service/ 4 tests
    
    history/ 4 tests
    
    shard/ 4 tests
    
    TestShardControllerSuite/ 4 tests
    
    go.temporal.io/server/service/history/shard/TestShardControllerSuite/TestReadiness_Blocked Inherited TestReadiness_Blocked
    
    go.temporal.io/server/service/history/shard/TestShardControllerSuite/TestReadiness_Error Inherited TestReadiness_Error
    
    go.temporal.io/server/service/history/shard/TestShardControllerSuite/TestReadiness_MembershipChanged Inherited TestReadiness_MembershipChanged
    
    go.temporal.io/server/service/history/shard/TestShardControllerSuite/TestReadiness_Ready Introduced here