[HOTFIX] disaggregate clumped messages from unix socket handler

• context: if node socket receives many messages at once, it will concatenate them all into one string and emit that as the payload of a 'data' event
• this causes us to fail to parse (and therefore DROP!) messages because the concatenated messages are not valid JSON
• fix: refactor dispatch to split incoming data on newlines and pass them to a (newly extracted) dispatchOne function for handling