Add a way to get the unresolved Response for corner case support

[MatthewAry]

So this is not completely finished. I am not good enough with TypeScript to figure out how to modify the Sign type in the src/treaty/type.ts file to explicitly return a Response type when getRaw: true is used. I spent hours trying to figure it out.

This PR modifies edenTreaty:

EdenTreaty.<1>.<2>.<n>.<method>({
    ...body,
    $query?: {},
    $fetch?: RequestInit,
    getRaw?: boolean // Will cause the return type to be simply the unread Response object
})

See https://discord.com/channels/1044804142461362206/1182023123852345364

I welcome any suggestions on how to make the type capabilities of edenTreaty more accurate when working with this feature.