Intent of error:_nil_value_in_list, error:_non-string_value_in_list

All 2 exact tests in this concept. Every test is marked by where it enters the hierarchy.

go.temporal.io/ 2 tests
- server/ 2 tests
  - common/ 2 tests
    
    searchattribute/ 2 tests
    
    sadefs/ 2 tests
    
    Test_DecodeKeywordList/ 2 tests
    
    go.temporal.io/server/common/searchattribute/sadefs/Test_DecodeKeywordList/error:_nil_value_in_list Introduced here
    
    go.temporal.io/server/common/searchattribute/sadefs/Test_DecodeKeywordList/error:_non-string_value_in_list Introduced here