fix(router): emit 'route-change' after navigation

[Antreesy]

☑️ Resolves

• Follow-up to fix(useGetThreadId): make reactive value more responsive #15704
• Wait for router navigation to successfully complete before emitting an event seems more reasonable:
  • token and threadId are updated globally according to route
  • navigation can be no longer interrupted
  • all current use cases are side-effects, which are safe to run after navigation:
    • SearchMessageTab, ThreadsTab - change sidebar tab, safe to do after
    • LeftSidebar - leave-join to signaling happens here, but safe to after
    • useGetMessages - defining a context, the place where it's important to do after 🟢

🖌️ UI Checklist

🖼️ Screenshots / Screencasts

🏚️ Before | 🏡 After

🏁 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]

Some things could have been avoided if this was added previously this week