Add vanity url support for embedded URLs

[joshuamsager]

Currently, only cdn.shopify.com links are rewritten when they are embedded in CSS/JS. This change also supports links that are served off of the shop's host.

WHY are these changes introduced?

Bugfix; without this, shops with vanity domains on their shop will have trouble loading their scripts locally.

Part of: #1859

WHAT is this pull request doing?

Simple gsub

How to test your changes?

Visit a shop with query param: ?force_vanity_url=true

Post-release steps

Measuring impact

How do we know this change was effective? Please choose one:

• n/a - this doesn't need measurement, e.g. a linting rule or a bug-fix
• Existing analytics will cater for this addition
• PR includes analytics changes to measure impact

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've made sure that any changes to dev or deploy have been reflected in the internal flowchart.

[github-actions]

Thanks for your contribution!

Depending on what you are working on, you may want to request a review from a Shopify team:

• Themes: @shopify/theme-code-tools
• UI extensions: @shopify/ui-extensions-cli
  • Checkout UI extensions: @shopify/checkout-ui-extensions-api-stewardship
• Hydrogen: @shopify/hydrogen
• Other: @shopify/cli-foundations

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	73.17%	4378/5983
🟡	Branches	69.56%	2013/2894
🟡	Functions	70.68%	1157/1637
🟡	Lines	74.58%	4183/5609

Test suite run success

1131 tests passing in 548 suites.

Report generated by 🧪jest coverage report action from 1eda576

[github-actions]

We detected some changes at either packages/*/src or packages/cli-kit/assets/cli-ruby/** and there are no updates in the .changeset.
If the changes are user-facing, run "pnpm changeset add" to track your changes and include them in the next release CHANGELOG.

[yknx4]

lgtm. lets wait for the owners approval

[amcaplan]

Didn't 100% figure out how to 🎩 but the code change is small and the test is pretty clear. I assume @yknx4 already did due diligence on the completeness of the fix.