Manage basket addition from Alias

[Tirodem]

Context

For retail use case, we need the seller to make basket addition through product alias (check #381 ).
Seller might be able to add product easily with a barcode scanner.

Implementation

Create a /admin/retail-cart interface

Limited access to admin users & POS Seat users.
Dont display admin header on this page.

Empty cart

Non-empty cart

Behavior

Barcode addition to basket should be easy and not require key / mouse action (or the lesser), so, by filling a known product alias:

• the addition to basket in qty = 1 should be done automatically once the input matchs an existing alias
  • so, no error management, if alias does not exist, do nothing (user will have to empty the input)
    • we can add a clear option on the input
      
• the addition should be displayed automatically on cart
• alias input must keep the focus in order to scan 2nd & more product code
  If qty > 1 to gain time, seller shall use mouse & qty selector.
  Checkout access might be done with mouse.

[Tirodem]

I totally forgot to say that alias must be unique from a product to another.
Happilly, actually, by bulk or edition or unique product, there's error management in backend :

It'll go as it is for a 1st version for error management.