Intent of operator_not_equal

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
  - common/ 3 tests
    
    persistence/ 3 tests
    
    visibility/ 3 tests
    
    store/ 3 tests
    
    elasticsearch/ 3 tests
    
    TestQueryConverter_ConvertComparisonExpr/ 1 test
    
    go.temporal.io/server/common/persistence/visibility/store/elasticsearch/TestQueryConverter_ConvertComparisonExpr/operator_not_equal Introduced here
    
    TestQueryConverter_ConvertKeywordComparisonExpr/ 1 test
    
    go.temporal.io/server/common/persistence/visibility/store/elasticsearch/TestQueryConverter_ConvertKeywordComparisonExpr/operator_not_equal Inherited operator_not_equal
    
    TestQueryConverter_ConvertKeywordListComparisonExpr/ 1 test
    
    go.temporal.io/server/common/persistence/visibility/store/elasticsearch/TestQueryConverter_ConvertKeywordListComparisonExpr/operator_not_equal Inherited operator_not_equal