HTTP methods must be uppercase

[rodoviti]

According to the HTTP specification (RFC 7231), HTTP methods are case-sensitive. However, because GET, POST, and PUT are the "original" and most common methods, many underlying networking libraries and proxies automatically normalize them to uppercase before they even reach your route handler/controller. But for extended HTTP methods (like PATCH), a request with lowercase method value may results in a 405 Method Not Allowed.
So, to be compliant to RFC 7231 spec, method defined here must be uppercased

PS: currently, this issue prevents the invocation of PATCH-method REST APIs implemented with Next.js using the App Router feature.

Depends on pagopa/io-ts-commons#428