GroverOptimizer with Sampler

[a-matsuo]

Summary

Add support of Sampler to GroverOptimizer

Addresses #425

• update codes
• update tests
• update docs
• add reno

Details and comments

[t-imamichi]

Thank you, @a-matsuo. I'm thinking of integrating this PR to #436.

[a-matsuo]

Sure, I'm fine with it. Let me finalize the codes.

[woodsp-ibm]

At one point I thought there had been discussion about changing things here so it used the Grover algorithm from Terra - I thought it was now possible since this was done long ago and the Grover implementation since then had become more capable where this could be done. Maybe as an alternate new path, while keeping the old more direct code this is more complex to achieve this time around - i.e. instead of a Sampler it would take a Grover (which itself would already be setup with a Sampler).

[a-matsuo]

Thx for the reviewing. I agree with that it is nice to use the Grover class in Terra. I believe it's possible since the Grover class can receive functions for iteration and is_good_state. So, we can dynamically change the iteration of the Grover operator in the algorithm by squashing the current code into iteration and is_good_state. (This might be a good issue for the qiskit advocate mentorship program. I don't have time right now. )

For GroverOptimizer, we need to change the variables of Grover dynamically. So, we can pass something like Grover(quantum_instance=quantum_instance) or Grover(sampler=sampler), but this doesn't make much difference, and I think passing a sampler looks better than passing Grover(sampler=sampler) to me.

[t-imamichi]

Since this PR is based on #436, I will merge this PR to #436.

[coveralls]

Pull Request Test Coverage Report for Build 3484791344

• 100 of 108 (92.59%) changed or added relevant lines in 7 files are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.09%) to 92.104%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
qiskit_optimization/algorithms/optimization_algorithm.py	18	19	94.74%
qiskit_optimization/deprecation.py	1	2	50.0%
qiskit_optimization/algorithms/grover_optimizer.py	48	54	88.89%

Files with Coverage Reduction	New Missed Lines	%
qiskit_optimization/algorithms/grover_optimizer.py	1	94.26%
qiskit_optimization/runtime/vqe_program.py	1	96.67%

Totals
Change from base Build 3482657244:	-0.09%
Covered Lines:	4374
Relevant Lines:	4749

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💛 - Coveralls

[t-imamichi]

I have merged it to #436. So, I close this PR.