It shouldn't be necessary to use the --assumeyes option when creating a
Toolbx container, if the corresponding image is already present in the
local containers/storage image store.  It's harmful to test it with the
option, even when it shouldn't be needed, because it's off by default
and most users won't enable it.

Therefore, it's better to test the most common scenario that most users
will encounter.

containers#1536

containers#1536

containers#1533

This will make it easier to propagate the exit codes of subordinate
processes through an exitError instance, when toolbox(1) is invoked
inside a container, and invocation is forwarded to the host.

Cobra doesn't honour the root command's SilenceErrors, if an error
occurred when parsing the command line for a command, even though the
command was found.  However, Cobra does honour SilenceErrors, if the
error occurred afterwards.

Therefore, to avoid setting SilenceErrors in each and every command, it
was set in the PersistentPreRunE hook (ie., preRun), which is called
after all command line parsing has been successfully completed.

containers#957