Update schedule page panels order and Shift swaps presentation

[raphael-batte]

Current logic: we add a swap interval and change the user both in the rotation and in the final schedule. (Apr 12 on the screen). This causes issues for OnCall users in obtaining information about people in the rotation.

Suggestion - example on Apr 16:

1. Change page blocks order to
   • final schedule
   • overrides and swaps
   • rotations
2. leave rotation w/o visual changes, add swap overrides and swaps and update the final schedule.

Slack topic