pc/consent: Fides.shopify integration function

[ssangervasi]

Closes #2052
Doc: https://ethyca.atlassian.net/wiki/spaces/EN/pages/2579038241/Shopify+fides-consent.js

Code Changes

• Fides.shopify integration function
• Extract fides-consent integrations into their own files
• Readme with more detail on integrations.

Steps to Confirm

• The doc's breakdown of the test page: https://ethyca.atlassian.net/wiki/spaces/EN/pages/2579038241/Shopify+fides-consent.js
• I'll update the test Shopify store's script with a built version of this PR so it will be able to use Fides.shopify() instead of the manual version I documented.

Pre-Merge Checklist

• All CI Pipelines Succeeded
• Documentation:
  • documentation complete, PR opened in fidesdocs
  • documentation issue created in fidesdocs
• Issue Requirements are Met
• Relevant Follow-Up Issues Created
  • Support third party integrations with Fides consent script - Facebook #2160
• Update CHANGELOG.md

Description Of Changes

This covers the limited consent options Shopify supports, with their async-loaded API feature. It's still up to the organization to decide what data use counts as "tracking".