Intent of branch_manager.go ×2

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
    
    ndc/ 4 tests
    
    TestBranchMgrSuite/ 4 tests
    
    go.temporal.io/server/service/history/ndc/TestBranchMgrSuite/TestCreate_MissingEventInBetween Inherited TestCreate_MissingEventInBetween
    
    go.temporal.io/server/service/history/ndc/TestBranchMgrSuite/TestCreate_NoMissingEventInBetween Inherited TestCreate_NoMissingEventInBetween
    
    go.temporal.io/server/service/history/ndc/TestBranchMgrSuite/TestGetOrCreate_BranchNotAppendable_MissingEventInBetween Inherited TestGetOrCreate_BranchNotAppendable_MissingEventInBetween
    
    go.temporal.io/server/service/history/ndc/TestBranchMgrSuite/TestGetOrCreate_BranchNotAppendable_NoMissingEventInBetween Inherited TestGetOrCreate_BranchNotAppendable_NoMissingEventInBetween