Consistency with JupyterLab: Clear output when a cell is queued for execution

[stuarteberg]

In JupyterLab, a cell's output is cleared immediately once the user has decided to re-run it, even though it may not be executed immediately due to other cells running in the queue. I'm having trouble adjusting to the VSCode UI, in which cell output remains until the cell has started execution. In VSCode, I find myself accidentally reading out-of-date outputs or error tracebacks before I realize that the cell is still waiting to re-execute.

I confess that this is a duplicate of #11585, which was closed over a year ago due to lack of interest. However, I wonder if it might garner more support now, with increasing numbers of users migrating away from JupyterLab to AI-enabled IDEs like VSCode.

(If it's poor etiquette of me to knowingly open a duplicate issue, then I sincerely apologize. I'm just not sure how to express my support for that feature request now that the original issue is no longer accepting comments or upvotes.)

[stuarteberg]

FYI, in case you want to upvote again:

@patrickmelix, @tabacof, @sergiocalde94, @zachmeador, @aysenurk, @MobisParkHeekang, @thisiswhereitype, @pamitabh