[REQ] [rust-reqwest-blocking] Return response headers when present in the response definition

[nponsard]

Is your feature request related to a problem? Please describe.

I have an API that returns no body and a location header linking to the newly created resource. The header is documented in the openapi specification file.
I would like to be able to get this header in the value returned by the generated function.

Describe the solution you'd like

The documented headers would be returned in a struct like a parsed body would.

Describe alternatives you've considered

Manually editing the code to read the header, but that would be needed every time we want to update the API.

Additional context

The definition looks like this

    post:
      responses:
        "201":
          headers:
            location:
              description: Where to find the newly added object.
              schema:
                type: string
          description: |
            Successful importation of the object
            e.g. "https://localhost/v1/obj/<random-id>".