[People] Canvas user search should index based on display name and sortable name

[samuel_malcolm]

Problem statement:

Currently if I user has a specified middle name in their 'full name' it's very difficult to search for them and find them based on their name. Because the search box only indexes based on full name. So if you dont know that it's John Doe Smith, and search John Smith, the former wont be a returned record. Even though the sortable name is what is printed in the UI

Proposed solution:

Add to the user_search.rb script query to allow the search pattern to be tested against display_name and sortable_name as well as full_name.

User role(s):

admin,instructor,ta,designer