Add Volcengine support for TTS and ASR services

- Introduced Volcengine as a new provider for both TTS and ASR services.
- Updated configuration files to include Volcengine-specific parameters such as app_id, resource_id, and uid.
- Enhanced the ASR service to support streaming mode with Volcengine's API.
- Modified existing tests to validate the integration of Volcengine services.
- Updated documentation to reflect the addition of Volcengine as a supported provider for TTS and ASR.
- Refactored service factory to accommodate Volcengine alongside existing providers.

engine/runtime/ports/tts.py

@@ -19,6 +19,10 @@ class TTSServiceSpec:
     api_key: Optional[str] = None
     api_url: Optional[str] = None
     model: Optional[str] = None
+    app_id: Optional[str] = None
+    resource_id: Optional[str] = None
+    cluster: Optional[str] = None
+    uid: Optional[str] = None
     mode: str = "commit"