[ Proposal ] Add toCurl() method to the Http class

[rashidlaasri]

Pretty simple, as it says in the title, would it be useful to add a new toCurl method to the Http class to get the cURL version of the request being sent. Useful for debugging and making sure the request is formatted and sending the data as expected.

Http::withHeaders([
            'username' => ':username',
            'password' => ':password',
        ])
        ->post(':url', :data)
        ->toCurl();

I am happy to PR it if needed.