When creating a new conversation in a 'Dialogue' activity, the people picker dropdown (a search-as-you-type interface) correctly shows that there are more results, but does not provide a way to view the next page of results.

How to reproduce:
1. In a course with more than 10 students, create (or open) an activity of type 'Dialogue' and open the activity page.
2. Click the 'Create' button to create a new conversation.
3. Click the arrow in the people selector ('Search potentials') to view students or type one or more characters into the search box to filter - pattern must match more than 10 users.

Expected behaviour:
If there are more than 10 students whose names match the entered pattern, paging buttons must be present to navigate to the next page of matches.

What actually happens:
The footer says 'Displaying 1-10 of <number of matches>', but there are no controls to go to the next page of matches.