Represent request method as enum instead of string

[hauleth]

With enumerable it makes it way easier to setup routing or in general match against request method. There is even built in std.http.Method enum that provides set of such methods available.

[egoholic]

I'm not sure if it makes sense because in a request a method is represented as a string and you need anyway to compare against string. For example, Golang's net/http package also defines methods as strings https://pkg.go.dev/net/http#pkg-constants