feat: implement adding to cart/removing from cart

[akrutsko]

Add product to cart / Remove product from cart

Description of changes 🗣️

• the application correctly identifies whether a product is already in the user's shopping cart when viewing the product page
• if the product is not already in the shopping cart, the "Add to Cart" button is active and can add the product to the cart
• if the product is already in the shopping cart, the "Add to Cart" button is inactive
• after successful removal, the user receives a confirmation message
• the application handles API errors gracefully, showing appropriate error messages if the removal operation fails.

Related Tasks 🔗

• ECOMM-4_07: [Product] Add Product to Cart Functionality for Non-Duplicated Products
• ECOMM-4_08: [Product] Remove Product from Cart Functionality

Special Instructions for the Reviewers☝🏻

n/a

Additional Information 📚

n/a

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