Add argument check to move_pauli_strings_into_circuit

[Acciaccatura]

The circuit_left argument of move_pauli_strings_into_circuit
should contain only a PauliStringPhasor-type operations.
Raise exception if that is not the case.

Fixes #7934

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.63%. Comparing base (f55763c) to head (e123cbe).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #7985   +/-   ##
=======================================
  Coverage   99.63%   99.63%           
=======================================
  Files        1110     1110           
  Lines      100020   100028    +8     
=======================================
+ Hits        99658    99666    +8     
  Misses        362      362           

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[pavoljuhas]

NB - I am moving the initial description here so the description can be reworded as a commit message

---

No tests exist for this change (AFAIK), perhaps we should add one? If so, I may need some guidance on what to test for as my QC knowledge is lacking.

It is sufficient to verify that the new exception is raised. I have tweaked the test in 3aa9879 so it corresponds to the addressed issue

Same with adding a docstring - shall we explicitly state what this function is doing, and/or what it requires, or is it OK to leave it as-is?

The function is in the contrib submodule and does not appear to be much used. For now it is OK to leave the docstring as is.

[pavoljuhas]

LGTM after pushing in a couple of tweaks.

@Acciaccatura - please check if this is good to go from your POV.