Fix an issue in shopify theme dev that was affecting assets/fonts loading on local servers

[karreiro]

WHY are these changes introduced?

This PR fixes a corner case related to #2094

WHAT is this pull request doing?

When the storefront_vanity_assets_url flag is activated, assets URL get a different shape. So, this PR modifies the regex for the assets and fonts middlewares in the shopify theme dev commands [1]. This change allows images to load directly from the disk when users access the local server (http://127.0.0.1:9292), rather than pointing to the CDN URLs.

[1] This flag doesn't affect theme app extensions.

How to test your changes?

• Activate the storefront_vanity_assets_url flag
• Run shopify theme init
• Open the theme directory
• Run shopify theme dev
• Notice that images and fonts load from the local server now

Before

After

Post-release steps

None.

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]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	71.35%	4645/6510
🟡	Branches	68.01%	2130/3132
🟡	Functions	69.33%	1214/1751
🟡	Lines	72.78%	4422/6076

Test suite run success

1087 tests passing in 564 suites.

Report generated by 🧪jest coverage report action from 99fc03f

[amcaplan]

Works like a charm!