Add download/upload chat messages to ChatInterface

[ahuang11]

I don't want to start the conversation from scratch so ideally, I can save a history of chat messages and re-upload it.

Or perhaps an easy way for users to add custom buttons to ChatInterface without dropping to ChatFeed, or even templates.

[ahuang11]

Prior to this, I believe there should be an export / method method on ChatFeed that supports two formats:

1. panel kwargs {"user": ..., "value": ..., "avatar": ...}
2. openai / langchain style {"role": "system", "content": "You are a helpful bot."}

1 for saving and restoring from previous chat
2 for fine tuning and inference:

from transformers import AutoTokenizer

tokenizer = AutoTokenizer.from_pretrained("mistralai/Mistral-7B-v0.1")
chat = [
  {"role": "system", "content": "You are a helpful bot."},
  {"role": "user", "content": "Hello, how are you?"},
  {"role": "assistant", "content": "I'm doing great. How can I help you today?"},
  {"role": "user", "content": "I'd like to show off how chat templating works!"},
]

print(tokenizer.apply_chat_template(chat, tokenize=False))

Then maybe a third method, save which outputs a JSON file?

[ahuang11]

cc: @MarcSkovMadsen for feedback