Unable to serialize Object

[esfomeado]

Issue Description

When using an Object Scalar the request is not serialized properly.

For instance we if set the codegen to not use the object mapper for the Object scalar and the object itself is an UUID the request will be unparsable but if the object itself is a Map it will work fine.
Now if we use the object mapper for the Object scalar and the object itself is an UUID the request will be parsable but if the object itself is a Map the request will be unparsable.
No matter the option used it will never work for all cases.

Steps to Reproduce

Use an Object Scalar and try to parse multiple objects.

Expected Result

The request should always be valid/parsable.

Actual Result

In some scenarios the request is unparsable.

Your Environment and Setup

• graphql-java-codegen version: 5.9.0
• Build tool: Gradle