Add Perplexity Node

[shige]

Task description

Add a new node for Perplexity AI. This node should allow users to interact with the Perplexity AI models within the node editor.

Background

The goal is to enable users to leverage Perplexity AI's capabilities directly within the node editor. This will expand the range of AI models available and allow for more diverse and sophisticated workflows. We specifically want to support the Perplexity provider offered by the Vercel AI SDK.

TODO (Optional)

• Create a new node type for Perplexity AI.
• Implement the necessary API calls to interact with the Perplexity API.
• Allow users to configure the Perplexity node with necessary parameters (model selection, prompt, etc.).
• Ensure the Perplexity node utilizes the existing PERPLEXITY_API_KEY environment variable for authentication.
• Thoroughly test the Perplexity node to ensure it functions correctly.

Additional notes (Optional)

The PERPLEXITY_API_KEY is already configured in Vercel environment variables. This node should leverage the Perplexity provider from Vercel AI SDK. This task is specifically for the Giselle team.