Add missing hermitian argument to backend.calculate_eigenvalues and backend.calculate_eigenvectors methods

[renatomello]

Closes #1447 together with qiboteam/qibojit#188. Tests should be run locally to verify that they are passing on GPUs.

The numpy, numba, pytorch, and tensorflow backends already had this argument in their methods, but abstract, cupy, and cuquantum did not. This fixes the issue.

Checklist:

• Reviewers confirm new code works as expected.
• Tests are passing.
• Coverage does not decrease.
• Documentation is updated.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.94%. Comparing base (df709ce) to head (efb3f6a).
Report is 9 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1448   +/-   ##
=======================================
  Coverage   99.94%   99.94%           
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  Files          81       81           
  Lines       11708    11708           
=======================================
  Hits        11701    11701           
  Misses          7        7           

Flag	Coverage Δ
unittests	99.94% <100.00%> (ø)

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