Jackson mapper default property inclusion should be "ALWAYS" to prevent null values from being omitted in query results

[bsara]

Currently, the object mapper created using ObjectMapperProvider & ObjectMapperConfigurer is unchanged before use. This includes the default property inclusion value of the ObjectMapper. It would never make sense to not have this value be anything other than JsonInclude.Include.ALWAYS since GraphQL query results are never to omit any requested property regardless of the value of the property.

In a project where both RESTful endpoints and GraphQL are used, the situation may arise where the RESTful endpoints are to omit properties from responses under certain conditions (e.g. omit all null values from the response). When this is the case and the project uses the same ObjectMapper for both the RESTful endpoints and the GraphQLServlet, then it would be most helpful to "ignore" the value set by the incoming ObjectMapper's default property inclusion value and set it to JsonInclude.Include.ALWAYS instead.