The nested class AddlShellCommands holds methods that encapsulate
the actual functionality from the related do_ method (e.g.
do_store_data calls self.store_data). This is already a good level
of separation but it does not allow us to call those methods from
programs that are not based on cmd2. Let's turn those methods into
functions so that non cmd2 applications have easy access to the
functionality of pySim.global_platform.
Let's also add a pySimLogger, so that we do not have to call
self._cmd.poutput
Related: SYS#6959
35ca46d8fe