Added minor error catching for entry/leave announcements

[RPiAwesomeness]

What does this change?

It adds a test to catch errors when announcement packets of user entries or departures from a stream's chat don't include the user attribute

Requirements

• [x] Only PG-rated language used (code, commits, etc.)
• [x] Descriptive commit messages
• [x] Changes have been tested
• [x] Changes do not break any existing functionalities