Add vision model support and related configurations in Assistant

- Introduce new fields in AssistantConfig, schemas, and database models to support vision capabilities, including `vision_enabled` and `vision_model_resource_id`.
- Enhance validation logic in routes to ensure proper handling of vision models and their requirements.
- Update the AssistantPage and related frontend components to include options for enabling vision understanding and selecting appropriate vision models.
- Modify database seed scripts to include vision-related data for assistants, ensuring consistent setup.
- Refactor related functions to integrate vision model handling in the audio-visual processing pipeline.

backend/models.py

@@ -42,6 +42,15 @@ class AssistantConfig(BaseModel):
     llm_values: dict = {}
     llm_secrets: dict = {}
     llm_support_image_input: bool = False
+    vision_enabled: bool = False
+    vision_model_resource_id: str | None = None
+    vision_model: str = ""
+    vision_llm_interface_type: str = "openai-llm"
+    vision_llm_values: dict = {}
+    vision_llm_secrets: dict = {}
+    vision_llm_support_image_input: bool = False
+    vision_llm_api_key: str = ""
+    vision_llm_base_url: str = ""
     stt_values: dict = {}
     stt_secrets: dict = {}
     tts_values: dict = {}