Breaking: Discount is applicable on sale category and not on menu category

Fix the import, etc on this.
While entering discount in sale, it checks the max allowed.

bookie/src/app/core/menu-category.ts

@@ -4,7 +4,6 @@ import { Product } from './product';
 export class MenuCategory {
   id: string | undefined;
   name: string;
-  discountLimit: number;
   isActive: boolean;
   isFixture: boolean;
   sortOrder: number;
@@ -14,7 +13,6 @@ export class MenuCategory {
   public constructor(init?: Partial<MenuCategory>) {
     this.id = undefined;
     this.name = '';
-    this.discountLimit = 0;
     this.isActive = true;
     this.isFixture = false;
     this.sortOrder = 0;

bookie/src/app/core/product.ts

@@ -8,8 +8,8 @@ export class Product {
   code: number;
   name: string;
   units: string;
-  menuCategory: MenuCategory;
-  saleCategory: SaleCategory;
+  menuCategory?: MenuCategory;
+  saleCategory?: SaleCategory;
   price: number;
   hasHappyHour: boolean;
   isNotAvailable: boolean;
@@ -25,8 +25,6 @@ export class Product {
     this.code = 0;
     this.name = '';
     this.units = '';
-    this.menuCategory = new MenuCategory();
-    this.saleCategory = new SaleCategory();
     this.price = 0;
     this.hasHappyHour = false;
     this.isNotAvailable = false;

bookie/src/app/core/sale-category.ts

@@ -3,12 +3,13 @@ import { Tax } from './tax';
 export class SaleCategory {
   id: string | undefined;
   name: string;
-  tax: Tax;
+  discountLimit: number;
+  tax?: Tax;
 
   public constructor(init?: Partial<SaleCategory>) {
     this.id = undefined;
     this.name = '';
-    this.tax = new Tax();
+    this.discountLimit = 1;
     Object.assign(this, init);
   }
 }