feat: icon added to alert button

[ClaraLpresta]

❓ 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

📝 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.

[cnavarro-prestashop]

It seems ok for me but if we begin to add every props of button in alert component, wouldn't that be better if we give possibility to precise a slot with only button component instead ? @mattgoud / @MikeLebeau your point of view on this please ?

[cnavarro-prestashop]

@ClaraLpresta : I close this pull request because it's a duplicata of #246

[mattgoud]

It seems ok for me but if we begin to add every props of button in alert component, wouldn't that be better if we give possibility to precise a slot with only button component instead ? @mattgoud / @MikeLebeau your point of view on this please ?

préférence slot pour ma part ...