fix: [Skeleton] #395 - display icons for img/video/graph variants

[mattgoud]

❓ Types of changes

Replace Material Icons by Material Symbols class for Skeleton component (fix #395)

• 📖 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

📝 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.