Redact events with sensitive data

When Puppet synchronizes a property it stores the historical, previous, and desired values in an instance of Puppet::Transaction::Event. The event is both sent to the Puppet master in the transaction report and is logged as part of the normal Puppet logging. When an event is created that contains sensitive data, these fields need to be redacted in some manner to prevent the plaintext values from being emitted in the aforementioned logging and reports.

Event objects also contain a message field that may contain sensitive information, but as far as the event is concerned this is an opaque string and thus cannot be redacted by the event itself.