Filebeat modules parse and remove the original message. When original contents is JSON, the original message (as is), is not even published by filebeat. For debugging, re-processing, or just displaying original logs, filebeat should be able to publish the original unprocessed contents as well.

• Add raw contents to log.message
• Add option to modules to keep original message in log.message. Enabled by default (document this as backwards incompatible change)
• Update json reader to also report original unparsed contents