Rocket FromForm support with IntoParams and refactoring ext arguments

[juhaku]

Currently there is no support for rocket FromForm using IntoParams.

Add support for this behaviour as demonstrated below and discussed here #139 which allows using IntoParams with FromForm rocket derive macro. Also refactor extension arguments so that there is only one type of extension arguments being used across the extensions #217.

#[derive(serde::Deserialize, FromForm, IntoParams)]
#[allow(unused)]
struct QueryParams {
    foo: String,
    bar: i64,
}

#[utoipa::path(
    responses(
        (status = 200, description = "Hello from server")
    ),
    params(
        ("id", description = "Hello id"),
        QueryParams
    )
)]
#[get("/hello/<id>?<rest..>")]
#[allow(unused)]
fn hello(id: i32, rest: QueryParams) -> String {
    "Hello".to_string()
}