feat(DropdownMenu): handle `color` prop

[Silver343]

🔗 Linked issue

44

❓ Type of change

• [ ] 📖 Documentation (updates to the documentation or readme)
• [ ] 🐞 Bug fix (a non-breaking change that fixes an issue)
• [x] 👌 Enhancement (improving an existing functionality)
• [ ] ✨ New feature (a non-breaking change that adds functionality)
• [ ] 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• [ ] ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Added a color prop with two options, white and `gray, customerised the theme baded on the color prop.

📝 Checklist

• [x] I have linked an issue or discussion.
• [ ] I have updated the documentation accordingly.

[benjamincanac]

@Silver343 I just made a major refactor of the components variant / color system: https://github.com/benjamincanac/ui3/pull/141 in which I remove all the white / black colors to only keep gray with multiple variants. I should have warned you but I didn't know I was gonna do this 😅

I guess we should apply the same concept for the DropdownMenu, ContextMenu, etc. Here is the Kbd now using a variant instead of a color: https://github.com/benjamincanac/ui3/pull/141/files#diff-97385f604c62eab3b9ee505e1ef570dcd2925d5624b3b6f7c3391162d2dffd40

We can brainstorm the name of the variant together if you want but I guess that would be outline (default) and subtle (the gray one) to be consistent.

[Silver343]

@benjamincanac No worries, I'll update the pr, definitely makes sense to align the variant names.

[Silver343]

Gonna close this PR and open a new one as this one as become very messy.