Hyper Method Override Middleware

A middleware for Hyper that overrides an incoming POST request with a method given in the request's _method query paramerter. This is useful as web browsers typically only support GET and POST requests, but our application may expect other HTTP methods that are more semantically correct.

The methods PUT, PATCH, and DELETE are accepted for overriding, all others are ignored.

The _method query paramerter can be specified in a HTML form like so:

```html

```

And the middleware can be applied to our Hyper service like so:

rust let service = MethodOverrideMiddleware::new(service);

Full example

Here's the example from the Hyper homepage with the middleware applied.

```rust use std::{convert::Infallible, net::SocketAddr}; use hyper::{Body, Request, Response, Server}; use hyper::service::{makeservicefn, service_fn};

async fn handle(_: Request) -> Result, Infallible> { Ok(Response::new("Hello, World!".into())) }

[tokio::main]

async fn main() { let addr = SocketAddr::from(([127, 0, 0, 1], 3000));

let make_svc = make_service_fn(|_conn| async {
    let service = MethodOverrideMiddleware::new(service_fn(handle));
    Ok::<_, Infallible>(service)
});

let server = Server::bind(&addr).serve(make_svc);

if let Err(e) = server.await {
    eprintln!("server error: {}", e);
}

} ```