Intent of TestBuildTrailerPairs_ProtoRoundTrip, TestBuildTrailerPairs_NonStringValues

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
  - common/ 4 tests
    
    rpc/ 4 tests
    
    interceptor/ 4 tests
    
    go.temporal.io/server/common/rpc/interceptor/TestBuildTrailerPairs_MixedSafeAndUnsafeValues Inherited TestBuildTrailerPairs_MixedSafeAndUnsafeValues
    
    go.temporal.io/server/common/rpc/interceptor/TestBuildTrailerPairs_NonStringValues Introduced here
    
    go.temporal.io/server/common/rpc/interceptor/TestBuildTrailerPairs_ProtoRoundTrip Introduced here
    
    go.temporal.io/server/common/rpc/interceptor/TestExtractMetadataFromTrailer_ProtoRoundTrip Inherited TestExtractMetadataFromTrailer_ProtoRoundTrip