Add Checkout entity and Rest

• addOrUpdate
• list
• findById
• delete

curl --location --request POST 'http://localhost:5000/checkout/addOrUpdate' \
--header 'Content-Type: application/json' \
--data-raw '{      
    "checkoutShoppingPosts": [
        {
            "shoppingPostId": 1,
            "quantity": 1,
            "isDelivery": true,
            "address": "una direccion"
        },
        {
            "shoppingPostId": 2,
            "quantity": 2,
            "isDelivery": true,
            "address": "una direccion"
        }
    ],
    "customerEmail": "another2@example.com"
}'

curl --location --request GET 'http://localhost:5000/checkout/list'

curl --location --request GET 'http://localhost:5000/checkout/findById/5'

curl --location --request DELETE 'http://localhost:5000/checkout/delete/6'