feat(core/button): add autofocus property

[nuke-ellington]

💡 What is the current behavior?

GitHub Issue Number: IX-1886 / closes #1531

🆕 What is the new behavior?

• Buttons can now have autofocus
• Modals can now automatically set focus on nested buttons

🏁 Checklist

A pull request can only be merged if all of these conditions are met (where applicable):

• 🦮 Accessibility (a11y) features were implemented
• 🗺️ Internationalization (i18n) - no hard coded strings
• 📲 Responsiveness - components handle viewport changes and content overflow gracefully
• 📄 Documentation was reviewed/updated (pnpm run docs)
• 🧪 Unit tests were added/updated and pass (pnpm test)
• 📸 Visual regression tests were added/updated and pass (Guide)
• 🧐 Static code analysis passes (pnpm lint)
• 🏗️ Successful compilation (pnpm build, changes pushed)

👨‍💻 Help & support

[changeset-bot]

🦋 Changeset detected

Latest commit: ba31212

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 4 packages

Name	Type
@siemens/ix	Patch
@siemens/ix-angular	Patch
@siemens/ix-react	Patch
@siemens/ix-vue	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

Report of strict check

src/components/utils/modal/modal.ts

• src/components/utils/modal/modal.ts(118,30): error TS18048: 'dialogRef' is possibly 'undefined'.: error TS18048: 'dialogRef' is possibly 'undefined'.