Merchant App: time estimation

When confirming an order estimate a delivery time that reaches the client's app.

That ticket is more complex than it sounds because we need to support the following:

0) The global setting of delivery time (could be we already have it, not sure). It's read from .env file (on the server or in the mobile shop, not sure) and used to display delivery time for all products from all merchants.

1) Per merchant setting of delivery time (could be we already have it, not sure). That will be used as default value when we display delivery time estimate for products in the mobile shop app

2) Per product setting of delivery time (think we don't have this yet). So if it set, in the mobile shop app we show that value instead of value defined for whole merchant (i.e. this value overrides the default for the merchant)

3) In the merchant app or in Admin UI, when the merchant confirms an order it should be possible to set (change the default value) Delivery time, which will be used to display delivery time estimate to Customer in the mobile shop.

4) The carrier should be able to manually adjust the delivery time estimate (to be done later at separate ticket)