Add delete app command #170
Description
We should include the app delete command in the cli. We decided at the beginning not to don't include that because the user could use the shell to just remove the app folder, but considering that we should do some checks before deleting an app, I think we should include that.
The command should be
arduino-app-cli app delete appID|path [--force] [--delete-data]
By default, the command will only delete an uninitialized app; with the force flag, the app will first be stopped and then deleted.
If an app has some data stored in the data dir, we should warn the user that they will lose their data, so we need to ask the user to delete the data, or we will delete it with the --delete-data flag.