[8.x] Add throwIf method in Client Response

[ahmadmayahi]

The throw method throws an exception if a server/client error occurs.

But there is no way to tell the throw to throw an exception if something evaluates to true.

For example:

->json()
->throw(App::isProduction); // This is not possible

The throwIf method throws an exception only if the condition evaluates to true:

->json()
->throwIf(App::isProduction);

Now, we can easily inspect the error message, during development, since no exception will be thrown.