Prevent from doing cli operations to unknown account

This MR introduces visitor pattern skeleton for operations. It allows to perform custom action on an operation based on implemented visitor.

This visitor pattern will allow us to define unknown_account_visitor pattern that will check for unknown account in transaction operations, and prevent from doing it, if any are found.

#288 (closed) - second part - save from cli command. First part - managing known account by cli command, is in separate MR !552 (merged)