chat: enabled chat streaming feature

[adityaomar3]

This PR adds the streaming feature by Open-AI assistants API.
Previous: Chats were concatenated together and displayed on screen, the wait time for replies in that approach was too long.
Streaming enables the communication of server sent events, which reduces the latency and wait time.
Below is a sample test-video displaying the working of stream.

streaming-2024-06-26_17.47.02.mp4

[rmackay9]

Thanks for this. This is the feature that I've most been looking forward to adding to the chat module!

I've tested this myself and it is working as expected.

In case anyone is interested in the details, the OpenAI documentation shows two different ways that streaming can be done. We chose to go with the first method shown below.

1. One method involves overriding the EventHandler class and using a with/as block

with client.beta.threads.runs.stream(
  thread_id=thread.id,
  assistant_id=assistant.id,
  instructions="Please address the user as Jane Doe. The user has a premium account.",
  event_handler=EventHandler(),
) as stream:
  stream.until_done()

2. Another method involves creating a run and then iterating over the stream events (see here and slide the "Streaming" slider to the right)

stream = client.beta.threads.runs.create(
  thread_id="thread_123",
  assistant_id="asst_123",
  stream=True
)

for event in stream:
  print(event)