Unwrap Tensor objects from Qiskit Nature as necessary

[garrison]

This doesn't quite pass CI yet. At least one more change is needed somewhere.

Fixes #406.

[garrison]

The remaining error is with this code block:

https://github.com/Qiskit-Extensions/circuit-knitting-toolbox/blob/84e2b14df16a6c8fce67003985d357389c595ff3/circuit_knitting/forging/cholesky_decomposition.py#L347-L353

Historically, two_body_overlap_integrals was indeed an ndarray, but using the latest qiskit-nature, is it now S8Integrals (from qiskit_nature/second_q/operators/symmetric_two_body.py) at this point. If I focus on the test_entanglement_forging_H2O test, then in both cases we have two_body_overlap_integrals.shape == (7, 7, 7, 7). However, the reshape fails on S8Integrals:

>       w_op = two_body_overlap_integrals.reshape(n_basis_states**2, n_basis_states**2)
E       ValueError: cannot reshape array of size 406 into shape (49,49)

[github-actions]

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• 3 of 5 (60.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.05%) to 92.385%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
circuit_knitting/forging/cholesky_decomposition.py	3	5	60.0%

Totals
Change from base Build 6845196627:	-0.05%
Covered Lines:	2960
Relevant Lines:	3204

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