T14: Add Product to shopping cart

[erturkemre]

• [x] When a product added to shopping cart, it should be added to reducer
• [x] If same product added more then one, then product count should be increased in shopping cart

ShoppingCart reducer

 ```js   
    cart: [
        {  count: 1, checked: true, product: { id: “1235”, … }  },
        {  count: 3, checked: true, product: { id: “1236”, … }  },
    ]
```

• [ ] All items in the cart should be seen on dropdown

  

[erturkemre]

will be task