Consider empty requestBody as valid if not required

[cvernerie]

In the OpenApi specification, request bodies are optional by default, unless required: true is declared explicitly.

So I think the BodyValidator should not throw an exception in case an optional request body is not provided in the request.

As well, if a requestBody is required in the spec but not provided in the request, we can directly throw an InvalidBody exception and not try to validate against the schema.

One consequence is that projects using the library might need to add required: true on their endpoints in order to keep the same validation behaviour.

[Sarke]

Same with required fields. As long as the required fields are present, it shouldn't fail because the optional ones are not present.

[marius-xentral]

what's the status here? validating a request with an empty body (RequestValidator->validate($request)) results in a JSON syntax error if requestBody - required: true is not set.