Bosonic logarithmic mapper

[ftroisi]

Summary

This MR introduces the Bosonic Logarithmic Mapper, which allows to map the BosonicOp class to the qubit space using binary encoding.
It addresses Issue #1345

Details and comments

See the issue above for more details on the reference papers

[coveralls]

Pull Request Test Coverage Report for Build 8735231706

Details

• 59 of 64 (92.19%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.04%) to 86.949%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
qiskit_nature/second_q/mappers/bosonic_linear_mapper.py	0	1	0.0%
qiskit_nature/second_q/mappers/bosonic_logarithmic_mapper.py	58	62	93.55%

Totals
Change from base Build 8721629367:	0.04%
Covered Lines:	9027
Relevant Lines:	10382

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💛 - Coveralls

[mrossinek]

I focused on design and docs in this review and did not check the derivations or math.

I left some comments and once addressed this will fit nicely with the other mappers.

[mrossinek]

Some phrasing and one more refactoring idea

[mrossinek]

Okay, last round. I took a look at the rendered docs and found some more things that need fixing. See comments below.

Finally, I found this one odd break statement which we should address. After that this is ready to go 👍

[mrossinek]

Thanks! A minor detail to comment on but that's it 🙂

I was wondering whether we should highlight the new ValueError in the release note, but I honestly don't think it is necessary.

[mrossinek]

Thanks a lot, @ftroisi! Great work 👍