Revert to R6 for streaming

[calderonsamuel]

Right now this is just a placeholder for the job. I wasn't able to find the time before (because of the LatinR conference), but I'll have some free time this and next week that should allow me to get this done. Sorry for the delay!

[calderonsamuel]

Good news @JamesHWade

At this point he have a working StreamHandler inside gptstudio_request_perform(). We are no longer writing and reading streams from disk! 🥳

So far I have encountered two problems:

1. We always need to click the settings button to not get them as NULL. I believe this is because it is rendered as a ModalDialog.
2. The user message gets recorded twice in the chat history. This of course renders it twice each time in the chat windows. (should be easy to fix)
3. The stream is still inconsistent, and sometimes breaks in the middle of a response. Once 1 and 2 are fixed it should be enough to merged this PR and ask users to try to break it.

I also think there are some things to improve in the skeleton building process, but that will become a separate issue

[calderonsamuel]

All ready to merge

fix #143 , fix #148

[JamesHWade]

Sorry for the delay, @calderonsamuel. My wife gave birth to twins last month, so I have been a bit preoccupied. Thank you for this fantastic contribution, as usual.

[calderonsamuel]

Sorry for the delay, @calderonsamuel. My wife gave birth to twins last month, so I have been a bit preoccupied. Thank you for this fantastic contribution, as usual.

Don't worry. Congratulations to you both!