Unified @mention names across Confluence

Summary

When a user is mentioned in a comment, Confluence will then show the user's full/display name. However, in All updates tab, we use username directly to represent mentioned user. See screenshot.

Steps to Reproduce

1. Go to a page, add a comment, in comment, mention a user. 
2. Go to Confluence Dashboard, click on "All updates" tab, notice the mentioned user is pure username text. 

Expected Results

Confluence to display user's full/display name in the All updates tab.

Actual Results

Confluence displayed user's username in the All updates tab.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available