[Feat] Enhance Qwen model with additional parameters and improved visual handling (#639)

* Enhance Qwen model with additional parameters and improved visual handling

- Added `system_prompt`, `interleave_visuals`, and `max_length` parameters to Qwen2_VL class.
- Simplified device assignment logic for single process scenarios.
- Improved visual processing by refining how visuals are handled and ensuring proper mapping to contexts.
- Enhanced message construction to support interleaving of visuals and text based on placeholders.
- Set default generation parameters and refined handling of generated outputs to ensure proper trimming and formatting.

* Refactor VisualPuzzles utility functions for improved readability and consistency

- Updated string formatting to use double quotes for consistency.
- Enhanced the `VisualPuzzles_doc_to_text` and `parse_response` functions for better clarity and structure.
- Simplified conditional checks and improved whitespace handling in response parsing.
- Ensured consistent handling of options and answers throughout the utility functions.

Author: Luodian