DSV tutorial

[orielkiss]

Error mitigation tutorial based on dual state verification. Outcome of Autumn 22 QAMP project #3.
(i tried to run the automatic tests using tox, and it seems some original code (such as dynamical decoupling) don't pass the tests),

[kevinsung]

Thanks for the pull request! I have updated the contributing guide to list our current criteria for considering submissions. Can you check that your submission fulfills the criteria?

[kevinsung]

Hi @orielkiss I think it makes to include this as a utility. It needs to be refactored though:

• tutorial_DSV.ipynb and associated files should be moved to docs/dual_state_verification/.
• dual_state_verification.py should be moved to qiskit_research/utils

As for the module code, a few initial comments:

• Please add type annotations to the function arguments
• Please make sure all publicly exposed functions and classes have docstrings that include documentation of the arguments. You can checkout the other code in utils/ for guidance.

[CLAassistant]

All committers have signed the CLA.