feat(settings): split default camera and microphone settings into separate toggles

[max65482]

☑️ Resolves

• Fix Split default camera and microphone settings into separate toggles #17202

AI (if applicable)

• The content of this PR was partly or fully generated using AI (Github Copilot, GPT-5.6 Luna)

🖌️ UI Checklist

🖼️ Screenshots / Screencasts

🏚️ Before	🏡 After

🚧 Tasks

• ...

🏁 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

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🛠️ API Checklist

🚧 Tasks

• ...

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not possible
• 📘 API documentation in docs/ has been updated or is not required
• 🔖 Capability is added or not needed

[Antreesy]

Thanks for the contribution!

Needs a backender to review it before continue.

From a quick glance - we can't just drop a config option from v20.1, it needs to be deprecated as minimum; existing values set on server can be migrated to maintain behaviour (previous: true -> audio: true + video: true), client should check if server supports new options, otherwise fall back to pre-existing one (e.g. if new client used with old server)

[max65482]

Thanks for the hint! Added backward and forward compatibility.
(Marking as draft since I haven't fully tested it yet.)