Allow Program Managers to Remove Interested Students from Program Roster

Issue Description

When navigating to Admin → Settings → Program Management → View Roster, Program Managers can view the list of interested students and add new interested students to the program.

Currently, there is no way to remove an interested student directly from the roster. Program Managers must search for the student through Student Search and manually uncheck the corresponding program interest checkbox.

Add the ability for Program Managers to remove interested students directly from the program roster.

Expected Behavior
Program Managers can remove an interested student directly from the View Roster page.
Removing a student updates their interested status for that program.
Program Managers no longer need to use Student Search to manually uncheck the student's interest.
The roster updates appropriately after the student is removed.

Start at Admin → Settings → Program Management → View Roster and trace the existing flow for adding interested students. Add the corresponding removal path so the student's interested status changes and the roster refreshes; verify that Program Managers can remove an interested student without using Student Search.

Written by the indexing model from the issue text.