Fixes #3823 Card Widget Deprecation Notices

[tadean]

Description

Generation of Card widget previews currently does not check if the URL is set before using it. This PR updates the check to verify if the value is present.

Related issues

#3823

How to test

• Enable az_demo
• Visit a node which contains cards, such as /pages/card-decks, or create a new page.
• Edit (or add) a card deck
• Create a card which has a link title, but no link URL.
• Save the page
• Edit the page
• Reopen the card deck
• Open and Collapse the individual card several times
• Check /admin/reports/dblog
• Verify that Deprecated function: str_starts_with(): Passing null to parameter #1 ($haystack) of type string is deprecated is not being generated
• Check for any regressions in card preview functionality
• Verify that a Card Link URL to a public file still works correctly, e.g. /sites/default/files/placeduck01.jpg

Types of changes

Arizona Quickstart (install profile, custom modules, custom theme)

• Patch release changes
  • Bug fix
  • Accessibility, performance, or security improvement
  • Critical institutional link or brand change
  • Adding experimental module
  • Update experimental module
• Minor release changes
  • New feature
  • Breaking or visual change to existing behavior
  • Upgrade experimental module to stable
  • Enable existing module by default or database update
  • Non-critical brand change
  • New internal API or API improvement with backwards compatibility
  • Risky or disruptive cleanup to comply with coding standards
  • High-risk or disruptive change (requires upgrade path, risks regression, etc.)
• Other or unknown
  • Other or unknown

Drupal core

• Patch release changes
  • Security update
  • Patch level release (non-security bug-fix release)
  • Patch removal that's no longer necessary
• Minor release changes
  • Major or minor level update
• Other or unknown
  • Other or unknown

Drupal contrib projects

• Patch release changes
  • Security update
  • Patch or minor level update
  • Add new module
  • Patch removal that's no longer necessary
• Minor release changes
  • Major level update
• Other or unknown
  • Other or unknown

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.
• My change requires release notes.