Allow TA to check in lab assistant from their user page

[vivrekar]

Currently, it seems that TAs can only check in lab assistants from the search screen via a button in the right-most column. (picture below)

This button is a bit difficult to find. Also, sometimes the TA might want to check a lab assistant in after clicking on their user page from the search screen. It would be nice to include a Check In button on this screen as well:

[ja5087]

I can work on this