mandos-ctl: Refactor: Move command list generation into argparse
* mandos-ctl (add_command_line_options): Don't simply set flags for each option; instead, add command objects to a "commands" list. (check_option_syntax): Rework to deal with an already-generated command list. (commands_from_options): Remove all code to generate command list, but add more code to move command.Deny ahead of command.Remove in command list. (command.PropertySetterValue.argparse): New; used in add_command_line_options. (Test_check_option_syntax): Refactor to pass actual string arguments to parse_args() instead of modifying an argparse.Namespace.