Buffering for non-tty output (non-interactive) in the vscode-integrated terminal

[sourishkrout]

This mimics what we do in the notebook and makes the terminal output more readable. Especially if both stdout and stderr are interspersed.

The difference is with buffering:

Before the change without buffering:

Example cell (interactive: false): https://gist.github.com/sourishkrout/d61c3226473afdc030951bdc167d15cd#file-01jkvp47gcjh2s6mgysf16j06b-md

[pastuxso]

At my end it works!