New features for Hayhooks

[mpangrazzi]

This is a sort of a "Roadmap part 2" for Hayhooks. I will list here any possibile improvements with a rough estimation of implementation difficulty.

🟥 - difficult
🟨 - medium
🟩 - easy

• 🟩 Add examples to programmatically create an hayhooks instance (to add custom routes or middlewares)
• 🟩 Add an overwrite option to update a pipeline without the need of restarting the server
• 🟥 Add support for requirements.txt-style extra dependencies
  • 🟥 To evaluate if each pipeline should run in separate environment
• 🟨 Add support for AsyncPipeline
  • 🟨 Add support for async methods in BasePipelineWrapper
  • 🟨 Implement async_streaming_generator utility
• 🟩 Add more examples
• 🟨 Support file uploads (e.g. for indexing pipelines)