Fixes for Shift deadlines during masquerade in Learning MFE

The change to masquerade in the courseware view allows the proper
viewing of the xblock from the perspective of the masqueraded user.
In this case, it allows a staff user masquerading as a learner to see
their shift dates calls to action inside the MFE (the old view already
had this set up). The second change allows the staff user masquerading
to reset the schedule of the learner being masqueraded via the CTAs