Hello, first of all thank you for this marvelous framework, it is really enjoyable to work with especially as I'm coming from Flask.

I noticed that there are methods for returning dictionaries for query parameters, path parameters and form data are also dictionaries. Suggestion is because currently we are losing the ability to set a default value if the header is missing, if it is - we get always None, but what if we need to have some default value?

My idea is to have something like this

request.headers.to_dict()

which will return a dictionary with all present headers

{
    "content-type": "application/json",
    "X-Forwarded-To": "some IP",
    ...
}

Is this possible to achieve?