fix: migrate typing state to Pinia

[Antreesy]

☑️ Resolves

• Migrate typing state from Vuex store to Pinia
• Standalone part, to offload and ease future migrations from vuex

AI (if applicable)

• The content of this PR was partly or fully generated using AI

🖌️ UI Checklist

🖼️ Screenshots / Screencasts

No changes

🏁 Checklist

• 🌏 Tested with different browsers / clients:
  • Chromium (Chrome / Edge / Opera / Brave)
  • Firefox
  • Safari
  • Talk Desktop
  • Integrations with Files sidebar and other apps
  • Not risky to browser differences / client
• 🖌️ Design was reviewed, approved or inspired by the design team
• ⛑️ Tests are included or not possible
• 📗 User documentation in https://github.com/nextcloud/documentation/tree/master/user_manual/talk has been updated or is not required

[DorraJaouad]

why in chat extras? I would expect it is related to participant entity hence a specific store for it

[Antreesy]

Maybe you're right, it doesn't belong to chat extras..

[Antreesy]

Moved participantsListTyping to component, to avoid including Vuex store into new Pinia store