fix(appointments): Make scheduled appointments meeting conversations

[nickvergessen]

• Server PR feat(talk): Allow to create conversations that are meetings server#59407
• Calendar PR fix(appointments): Make scheduled appointments meeting conversations … calendar#8127

Steps

1. Create an "Appointments schedule" with Talk conversation option
2. Book a meeting and confirm it

Before	After
Conversation is always visible	Conversation is only visible when the meeting is close or list is filtered for meetings
Conversation persists after the call	Conversation expires after 28 days

🏁 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