[UHN-BS-13] Tests for all Responder Endpoints

[mankitkong]

• Create a workflow test on:
  • Create 2 accounts (A, B)
  • In A, search for B (verify B shows up)
  • In A, add B as responder (verify B added)
  • In A, remove B as responder (verify B removed)
• Do the same for adding a batch of responders (this is a little more complicated)