Fix cytoscape send API

[millenr]

This pull request introduces significant improvements to how synthesis graphs and routes are sent to Cytoscape from the backend, along with a minor frontend update to maintain compatibility. The backend now supports sending all routes and full graphs as separate networks in a single request (multi-network mode), with robust auto-detection and naming logic for graphs and routes. The frontend is updated to explicitly request single-route mode to preserve previous behavior for UI actions.

Backend: Enhanced Cytoscape Network Upload Logic

• Added support for sending all available synthesis graphs and all routes as separate networks in one request, including improved error handling and results aggregation. [1] [2]
• Improved graph selection logic in convert_to_cytoscape_json to auto-detect the appropriate synthesis graph, falling back through multiple keys if needed.
• Refined the naming logic for Cytoscape networks to use target molecule identifiers and reaction steps, with clear differentiation between full graphs and routes.
• Extracted network upload and layout logic into a helper function for clarity and reuse, and improved error reporting for failures. [1] [2] [3]

Frontend: Compatibility Update

• Updated the sendToCytoscape helper to explicitly set send_all_routes=false, ensuring single-route upload behavior for UI actions remains unchanged.