Unify information stored on the express request object with the infor…

[nazrhom]

…mation we obtain parsing the request url/body.

Nothing changes when dealing with a single request, the objects are now consistent when responding to a batch request.

Change-type: patch

[ghost]

@nazrhom, status checks have failed for this PR. Please make appropriate changes and recommit.

[nazrhom]

@Page- ~~The reason is that I was thinking that the information we might want to pick from req is "less fixed", we might want to rely on other features later and would have to modify this code~~ This is not really valid, as we don't want to clone the whole req, so we still have to pick properties in this spot and eventually change it later if we need to add any. On the other hand the information we want to set the other way, is essentially limited to what we learn on the OData parse, so method, url and body (+ we could also add some extra logic for headers as pablo was interested in doing batch of requests with different api keys). It also makes the change less invasive as we don't have to modify all the hooks