Improve the clarity of notifications in the QR code scanning feature:
1. Permission handling:
- Show notification when screen recording permission is missing
- Automatically open system settings for permission grant
2. Enhanced scanning status notifications:
When no QR code found:
- Title: "Scanned X displays"
- Subtitle: "No QR codes found"
- Body: "Try adjusting the QR code position on your screen"
When invalid QR codes found:
- Title: "Found X QR code(s)"
- Subtitle: "No valid Shadowsocks URLs"
- Body: "QR codes found are not Shadowsocks configuration"
When valid QR codes found:
- Title: "Found X Shadowsocks URL(s)"
- Subtitle: "Scanned X displays, found X QR codes"
- Body: "Successfully added X server configuration(s)"