Simulation tests for each of purification protocol.

[Naphann]

Objective: Currently, we have a lot of purification protocols defined inside QuISP. In order to create a better development cycle and to gain more confidence in our code base, we want more simulation tests which would serve as a snapshot for when code changes.

Suggested test cases: There is already an X error purification simulation defined in the simulation test, we would want to test against

• no error scenario (should always pass)
• Werner state (depolarizing channel) error
• Biased error (3 cases for X, Y, and Z channel error)