Add origin to channel pricing

[loevgaard]

This PR tries to aid in fixing a weird bug where manually_discounted is being set to true although it shouldn't ;)

[codecov]

Codecov Report

Merging #59 (90cbde1) into master (5a5d571) will not change coverage.
The diff coverage is 0.00%.

❗ Current head 90cbde1 differs from pull request most recent head af013a8. Consider uploading reports for the commit af013a8 to get more accurate results

@@           Coverage Diff            @@
##             master     #59   +/-   ##
========================================
  Coverage      0.00%   0.00%           
- Complexity      220     223    +3     
========================================
  Files            38      38           
  Lines           934     947   +13     
========================================
- Misses          934     947   +13     

Impacted Files	Coverage Δ
...ner/UpdateManuallyDiscountedPropertySubscriber.php	0.00% <0.00%> (ø)
src/Model/ChannelPricingTrait.php	0.00% <0.00%> (ø)

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