UHF-X: Add original alt attribute to all images

[Arkkimaagi]

UHF-X

We currently have no visibility to actual alt attributes.

What was done

• This adds original alt to data-alt-original attribute so that we can debug it.

How to install

• Make sure your instance is up and running on latest dev branch.
  • git pull origin dev
  • make fresh
• Update the HDBT theme
  • composer require drupal/hdbt:dev-UHF-X_get_original_alt
• Run make drush-cr

How to test

• Check that this feature works
• Check that code follows our standards

[khalima]

🚀

[github-actions]

⚠️ Visual regression found! Please check if this change is wanted or accidental. You can check the output here: https://city-of-helsinki.github.io/drupal-hdbt/pull/912/html_report/