no-config debugging should exit script on debug cancel

[eleanorjboyd]

after starting a no-debug config session, the UI for the debug session appears with the stop button. Using this stop button should cancel the script, exiting it and stopping it from continuing, instead of just disconnecting the debugger.

[eleanorjboyd]

design proposal, idea by @karthiknadig:
Edit the type of debug session created to be of type "launch" instead of "connect" to allow the debugger session to control the session and cancel the script on debug cancelation.

[karthiknadig]

If the launch style does not work then we may need a switch in debugpy. Something like --exit-on-disconnect

[eleanorjboyd]

fixed on debugpy side, updated version to align here: cba78e3