Add support for running a web app with the run button

[isidorn]

Testing microsoft/vscode-python#22300

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def root():
    return {"message": "Hello World"}

If I click on the Editor Run action in the top right, the app is not actually run.
I have to go through the debug flow to choose Fast API to actually setup a proper launch.json

Could we improve the run experience so it also works?

[github-actions]

Thanks for the feature request! We are going to give the community 60 days from when this issue was created to provide 7 👍 upvotes on the opening comment to gauge general interest in this idea. If there's enough upvotes then we will consider this feature request in our future planning. If there's unfortunately not enough upvotes then we will close this issue.

[luabud]

@isidorn I renamed the issue to be more generic, let me know if it doesn't represent the request accurately though and I can re-edit!

[isidorn]

Makes sense, thank you!