[Theme] Show preview url for gift cards in the initial server logs

[frandiox]

WHY are these changes introduced?

The gift card preview URL is somewhat unknown. With this, we start showing it in the initial server logs:

WHAT is this pull request doing?

How to test your changes?

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

[github-actions[bot]]

Thanks for your contribution!

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

• Themes: @shopify/advanced-edits
• UI extensions: @shopify/ui-extensions-cli
  • Checkout UI extensions: @shopify/checkout-ui-extensions-api-stewardship
• Hydrogen: @shopify/hydrogen
• Other: @shopify/app-inner-loop

[frandiox]

@karreiro I'm not sure what you meant with handling the /123/preview in the backend but we can keep the conversation here and iterate 🙏

[github-actions[bot]]

Coverage report

St.:grey_question:	Category	Percentage	Covered / Total
🟡	Statements	72.73% (+0.02% 🔼)	8563/11774
🟡	Branches	69.72% (+0.03% 🔼)	4205/6031
🟡	Functions	71.69%	2211/3084
🟡	Lines	73.06% (+0.02% 🔼)	8105/11094

Test suite run success

1947 tests passing in 876 suites.

Report generated by 🧪jest coverage report action from 4f1e612030494520a060716b199eb046710e5bc7