Improve JellyChat Experience

[0ptim]

Use LangChain agents and tools to give the LLM access to live on-chain data using the ocean API.

• [x] Try to use gpt-3.5-turbo for the agent instead of text-davinci-003 to drive API costs down.
• [x] Give the agent or the final output more personality. It should know, that it is Jelly and behave like one.
• [x] Make sure that each client session has their own window memory.
• [x] Fix follow-up questions
• [x] Final testing
• [x] Go-Live