Return output and code from context.run

[pawamoy]

Is your feature request related to a problem? Please describe.
One might want to store the output of a command in a variable while in a duty. Currently it's not possible to use ctx.run for that because it doesn't return anything.

Describe the solution you'd like
Ideally ctx.run would return something similar to subprocess.run: an object containing the output and return code of the command. This way, we can still use ctx.run normally, and if needed store its result in a variable for further processing.

Describe alternatives you've considered
Running subprocess manually. It feels redundant.

Additional context
failprint will have to be modified as well, to return both output and exit code of a command.