feat(root-layout): DLT-1878 add scrollbar directive to root layout

[ninamarina]

feat(root-layout): DLT-1878 add scrollbar directive to root layout

Obligatory GIF (super important!)

🛠️ Type Of Change

These types will increment the version number on release:

• Fix
• Feature
• Performance Improvement
• Refactor

📖 Jira Ticket

DLT-1878

📖 Description

Adds custom scrollbar to root layout

💡 Context

📝 Checklist

For all PRs:

• I have ensured no private Dialpad links or info are in the code or pull request description (Dialtone is a public repo!).
• I have reviewed my changes.
• I have added all relevant documentation.
• I have considered the performance impact of my change.

For all Vue changes:

• I have added / updated unit tests.
• I have made my changes in Vue 2 and Vue 3. Note: you may sync your changes from Vue 2 to Vue 3 (or vice versa) using the ./scripts/dialtone-vue-sync.sh script. Read docs here: Dialtone Vue Sync Script
• I have validated components with a screen reader.
• I have validated components keyboard navigation.

🔮 Next Steps

📷 Screenshots / GIFs

🔗 Sources

[github-actions]

Please add either the visual-test-ready or no-visual-test label to this PR depending on whether you want to run visual tests or not.
It is recommended to run visual tests if your PR changes any UI. ‼️

[github-actions]

✔️ Deploy previews ready!
😎 Dialtone preview: https://dialtone.dialpad.com/deploy-previews/pr-541/
😎 Dialtone-vue 2 preview: https://dialtone.dialpad.com/vue/deploy-previews/pr-541/
😎 Dialtone-vue 3 the preview: https://dialtone.dialpad.com/vue3/deploy-previews/pr-541/