Pass cart object into completed cart actions prop

[grantkang5]

Is there a reason for not passing the cart object into event callbacks provided in CartProvider?

onCartActionComplete(context, event) {
      const cartActionEvent = event.payload.cartActionEvent;
      try {
        switch (event.type) {
          case 'RESOLVE':
            switch (cartActionEvent.type) {
              case 'CART_CREATE':
                return onCreateComplete?.(context?.cart);
              case 'CARTLINE_ADD':
                return onLineAddComplete?.(context?.cart);
              case 'CARTLINE_REMOVE':
                return onLineRemoveComplete?.(context?.cart);
              case 'CARTLINE_UPDATE':
                return onLineUpdateComplete?.(context?.cart);
              case 'NOTE_UPDATE':
                return onNoteUpdateComplete?.(context?.cart);
              case 'BUYER_IDENTITY_UPDATE':
                if (countryCodeNotUpdated(context, cartActionEvent)) {
                  customerOverridesCountryCode.current = true;
                }
                return onBuyerIdentityUpdateComplete?.();
              case 'CART_ATTRIBUTES_UPDATE':
                return onAttributesUpdateComplete?.();
              case 'DISCOUNT_CODES_UPDATE':
                return onDiscountCodesUpdateComplete?.();
            }
        }

The callback props in CartProvider help with relaying events to sequence actions like toggling a sidecart drawer. It'd be great if the updated cart object is passed so that we also use it to pass external events or handle third party apis from the client.

<CartProvider
  onLineAddComplete={(cart) => {
    window.dispatchEvent(new CustomEvent('cart:line-add:complete', { detail: cart } ));
  }}
>

[blittle]

I don't remember any specific reason. Happy to accept a PR.