Add shop level settings for storefront

/**

• Default limit of featured panel
  */
  int FEATURED_LIST_SIZE = 15;

/**

• Default limit of recommendation panels (newarrival, recently viewed)
  */
  int RECOMMENDATION_SIZE = 5;

/**

• Default product count in one row on category and search pages
  */
  int PRODUCT_COLUMNS_SIZE = 2;

/**

• Default sub categories count in one row on category and search pages
  */
  int SUBCATEGORIES_COLUMNS_SIZE = 2;