Show User's Job Title Instead of Job Role in Conversations and Updates

Currently, when you hover over a user's name, or start to @ mention them in an update, the preview text will show their user name plus their primary job role. 

This causes confusion for most of our user base, who are expecting to see the user's job title instead of the job role. We get questions about this all the time.

Not everyone updates their profile with a job title, so I think this feature could work by showing the user's job title if it exists, but then it can show the primary job role if the job title does not exist.