Use short_name instead of name for student-student interactions

[Q-Bea]

Changes user.name to user.short_name (or user.shortName) on the PeopleList and PeopleDetails pages when a student is viewing the details of another student.

Rational:

• This mimics the behaviour of the canvas web client (at least in my experience)

• "Short name" can also be used a "preferred name" by individuals of various demographics. It is not necessarily safe to assume that ones given name (.name) corresponds with how they wish to be referred as (.short_name).

• Teachers will still see the name as before, but it may also be worth adding the ability for them to see both a student's preferred and given names.

Note:

• This is my first time interacting with this codebase and there are probably other changes to be made in order to stay consistent. I don't know where to look, though, and I don't have the ability to test the app on my devices.