[BUG][Java][Vert.x] `JsonNullable` in request body model class generates invalid requests

Created by: jekkel

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Description

If a request model class uses a optional nullable field it get's wrapped in a JsonNullable<T>. This is perfectly fine. But the vert.x client then uses an ObjectMapper instance which lacks the registration of the JsonNullableModule required for the intended behaviour of differentiation between null and absent.

openapi-generator version

4.x, master

OpenAPI declaration file content or url

Command line used for generation

Steps to reproduce

Related issues/PRs

#5732