feat: [alert] UT for CTA icon

[ThbPS]

❓ Types of changes

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality)
• 📦 New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Unit test for CTA button icon in alert component
Related to #246

📝 Checklist

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes
• The component exists on old Prestashop UIKit and my pull request on migrating documentation is accepted.

[mattgoud]

Hello @ThbPS , sorry for the late comment regarding your PR, but there were still design questions about this component and so I suggest you close this PR replaced by #381. Tell me if it suits your needs (i put you reviewer)