Keep sample.tracking.config as a pure json file

This config file contains currently a require that might cause problems:

const STATUS = require("../app/models/status.js");

const MXExperimentPlan = [
  {
    header: "Space G.",
    name: "space_group",
    type: "select",
    values: ["True", "False"],
  },
  {
    header: "a",
    name: "unit_cell_a",
    type: "string",
  },

Status is indeed a json file