feat: Integrate Wavoip for voice call functionality

- Added Wavoip integration to support voice calls within the application.
- Introduced `wavoipToken` in various DTOs and models to manage authentication.
- Updated `ChannelStartupService` to handle Wavoip settings and events.
- Enhanced `BaileysStartupService` to utilize Wavoip for call signaling.
- Updated CHANGELOG.md to version 1.8.7.

src/api/dto/settings.dto.ts

@@ -6,4 +6,5 @@ export class SettingsDto {
   read_messages?: boolean;
   read_status?: boolean;
   sync_full_history?: boolean;
+  wavoipToken?: string;
 }