Allow creating a new terminal when running python file

[brettcannon]

Expected behaviour

Clicking on the run button runs the file

Actual behaviour

Nothing happens if another file is already running

Steps to reproduce:

[NOTE: Self-contained, minimal reproducing code samples are extremely helpful and will expedite addressing your issue]

1. Run a python file which keeps running (like an API)
2. Open another file (like one sending a request to the API)
3. Try to run it

(Originally from @claell who was part of the botched feature request conversion.)

[claell]

@brettcannon what is the current state? The original issue is closed (#16354) and also the follow-up one based on this discussion is closed again (#16496). Are you moving feature requests back into issues or not?

[brettcannon]

Nope, we backtracked on the idea after we discovered "Create issue from discussion" midway through the transition. So this discussion is the right place.

[lqdflying]

I thought that Running new Python file in either a new terminal or a terminal not running any Python file currently is a useful feature.
for example: run a socket server python file in a terminal and it would pending and listen a port,but you can't run the client python file on the same terminal.
In this scenario , if the client file could be running automatically in a new terminal is very convenient for me.

[brettcannon]

Moved (back) to #16354 (turns out no one else uses Discussions for feature requests, so need them as issues to be able to route them to the appropriate place).