Extend VF2Layout with 2-qubit-noise-scoring

[1ucian0]

This PR allows the user to set a scoring function in VF2Layout. A new two_q_score fidelity approximation function suggested by @czachow in https://github.com/Qiskit/qiskit-terra/pull/5075/files#diff-962c8087c2dc22fc3a88cc625c7fce565659b0c753ad21e0b8ccac0fa06a6249 was added.

• More testing
• Reno

[coveralls]

Pull Request Test Coverage Report for Build 1975650525

• 33 of 36 (91.67%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.005%) to 83.46%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
qiskit/transpiler/passes/layout/vf2_layout.py	33	36	91.67%

Totals
Change from base Build 1969439195:	0.005%
Covered Lines:	52414
Relevant Lines:	62801

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💛 - Coveralls

[mtreinish]

You might want to take a look at: #7776 I updated the heuristic layout scoring used by DenseLayout there to be general for all 2q and 1q operations in the target (I'm updating vf2layout to use a target in #7735 but I left adjusting the scoring for this PR). We can probably use some of the same heuristic here.

[mtreinish]

I think we can close this as stale, I had to add approximate scoring that factored in 2 qubit error rates as part of #7862 and I just pushed up #7991 to unify the scoring between VF2PostLayout and VF2Layout.

[czachow]

Sounds good to me!