RecordBuilder.withRecord(final String name, final Record value) doesn't accept null value

We can't add a null value in a sub-record entry of a record since the schema of the sub record is retrieved from the given value:
https://github.com/Talend/component-runtime/blob/0629e8f19fbfa2146958a760c226e0adb9e7f7f5/component-runtime-impl/src/main/java/org/talend/sdk/component/runtime/record/RecordImpl.java#L303