Autopkgtest added for package staden

[harish chavre]

Hi team,
I have added autopkgtest for the staden package [0]. The tests  try to include 
coverage for both the CLI and the graphical interface. Please take a moment to 
review and share any feedback or suggestions.
[0]https://salsa.debian.org/med-team/staden/-/commit/d540fd92b916d478c0c6e7b75d1db97f823c3ada
Thanks,
Harish