Set cartItem unit price before giftcard creation

[jum4]

Related to #193

[codecov]

Codecov Report

Merging #194 (13401d9) into 0.12.x (a70f927) will increase coverage by 1.51%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             0.12.x     #194      +/-   ##
============================================
+ Coverage     45.75%   47.27%   +1.51%     
  Complexity      501      501              
============================================
  Files            94       94              
  Lines          1567     1576       +9     
============================================
+ Hits            717      745      +28     
+ Misses          850      831      -19     

Impacted Files	Coverage Δ
src/Form/Extension/AddToCartTypeExtension.php	60.86% <100.00%> (+60.86%)	⬆️

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[loevgaard]

@Roshyo: How did this work in 0.11? Why has it changed? Do you know that?

[Roshyo]

It stopped working when we started to allow GC with custom amounts.
Previously, we were creating the GC from the OrderItemUnit when placing the order. Now we do it when creating the Order (cart) and the Order Item Unit has no price yet, since it is assigned by Sylius later.
Perhaps an other fix would be to change the GC creation just after this price assignment (from order processor) but not sure if it would raise more problems or not.

[loevgaard]

Thank you @jum4 and @Roshyo 🎉