[Critical] Backend Order Creation fails with variants

[Cruiser13]

Q	A
Bug report?	yes
Feature request?	no
BC Break report?	no
RFC?	no

We noted this issue in Coreshop 2.1.6 but it is reproducable on the current coreshop demo aswell.
For preparation enable inheritance and allow variants for CoreShopProduct class.

Create a variant of a product at coreshop:

The price is set by the parent product:

Use the Backend Order Creation and add the variant product to it:

It'll show a price of 0 Euro and it'll now show a name.

A fast fix including coreshop 2.1.6 or a pointer on where to fix this would be awesome!

[Cruiser13]

I added a fix proposal in PR but I'm not sure if this is the best way to solve it.