[MenuGroup] Converted to a functional component

[AndrewMusgrave]

WHY are these changes introduced?

More context here

This open in a tab, will polish and request reviews after hack days.

[github-actions]

💦 Potential splash zone of changes introduced to src/**/*.tsx in this pull request:

Files modified	2
Files potentially affected	3

Details

All files potentially affected (total: 3)

• /src/components/ActionMenu/ActionMenu.tsx
• /src/components/Page/components/Header/Header.tsx
• /src/components/Page/Page.tsx

📄 UNRELEASED.md (total: 0)

Files potentially affected (total: 0)

🧩 src/components/ActionMenu/components/MenuGroup/MenuGroup.tsx (total: 3)

Files potentially affected (total: 3)

• /src/components/ActionMenu/ActionMenu.tsx
• /src/components/Page/components/Header/Header.tsx
• /src/components/Page/Page.tsx

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