The quantization of the interpolation key was only used by the LSC
algorithm. There it lead to difficult to read code was removed. As there
is no remaining user of it, drop it from the Interpolator class.
While at it, cleanup the includes.
Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
