Add option to ignore invalid records in scribe output plugin

Pretty straightforward, and the code was essentially stolen from the scribe input plugin.
Sorry, copy/paste error. :(

I copied from https://github.com/fluent/fluent-plugin-scribe/blob/8df077902a09b2ea715cae3608bc0cdc3b06b502/lib/fluent/plugin/in_scribe.rb#L137

Do you have a suggestion for a better format? Is "got invalid record (#{e.class.name}): #{msg}" sufficient? Or should I just log the whole exception?