[Enhancement]: Add product validation for when attempting to update an item's quantity should the product no longer exists about co-cart HOT 4 CLOSED

@nicelittlethings Hopefully this fixes the issue. cart-rest-api-for-woocommerce-v3.7.7-beta.1.zip

from co-cart.

After further reviewing. As the item no longer exists, the cart has already updated when checking for changes before the request proceeds with updating the item. Meaning that we don't need to add additional validation but reorder a validation that should have been running first to see if there is any data to validate to begin with.

This prevents any uncaught errors as we don't need to proceed with the update but return the error status.

from co-cart.

@nicelittlethings This should be better for you if you had already downloaded and tried beta 1 that I uploaded previously. cart-rest-api-for-woocommerce-v3.7.7-beta.2.zip

from co-cart.

You should get the following response when trying to update an item in cart that is no longer there.

{
    "code": "cocart_item_not_in_cart",
    "message": "Item specified does not exist in cart.",
    "data": {
        "status": 404
    }
}

from co-cart.