fix: NewRoute/NewBaseRoute to take engine not just OpeAPI for accepted content types

[dylanhitt]

Relates to #333

Somewhere along implementing support for different engines this was lost. This is a bit disruptive as it's changing the NewRoute/NewBaseRoute. The other option would be to place acceptedContentTypes on our OpenAPI struct I could go either way. We wouldn't be changing the NewRoute and NewBaseRoute API in the case of the later, but again we'd need to support yet another nested structure with it's own options. I think flattening in the Engine is OK, I guess 🤷.

So the options are

1. This PR. Just be fine with configuration occurring on the engine struct
2. Place acceptedContentTypes in the OpenAPI struct. We can could then do something like

func WithRequestContentType(consumes ...string) func(*Engine) {
	return func(e *Engine) { e.OpenAPI.acceptedContentTypes = consumes }
}

3. Place acceptedContentTypes in the OpenAPI struct. And expose a WithOpenAPIOptions. At this point we're nesting pretty deep...
4. This could exist on the OpenAPIConfig struct as well. Then engine would still need to be passed to the New*Route funcs.

Cheers

[dylanhitt]

I'm going to go ahead and merge this unless anyone objects.

[EwenQuim]

Looking at it again right now

[EwenQuim]

Perfect. Sorry for the long review delay!

[dylanhitt]

Perfect. Sorry for the long review delay!

Thank you. Sorry been a bit impatient. Been thinking about #341 a bunch and i know this would cause conflicts.