Remove the TupleFlattener in favour of native HList operations

[alexflav23]

After we remove the ~ operator we have inherited from Anorm in favour of shapeless.HList, we can successfully remove the entire implementation of Tuple flatteners for the various arities, as they are nothing but Tupler.Aux which already existing in Shapeless, which would allow us to convert an HList to a Tuple using macro derivation hidden away from us, instead of having to write a lot of boilerplat.e