Add binary operation specialization

[Ericgig]

Add binary operations between JaxArray: matmul, add, sub, kron, multiply, and binary operation between JaxArray and scalar: mul, pow.

[coveralls]

Pull Request Test Coverage Report for Build 3203863830

• 51 of 54 (94.44%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+2.5%) to 91.525%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/qutip_jax/binops.py	44	47	93.62%
<!--	Total:	51	54	94.44%	-->

Totals
Change from base Build 3160050711:	2.5%
Covered Lines:	108
Relevant Lines:	118

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💛 - Coveralls

[Ericgig]

@quantshah Could you add your new tests in another PR instead of pushing it here. Usage test and adding specialization don't have to be done together.

[quantshah]

Everything looks good here except that we cannot pass QuTiP objects to and from functions that require JIT compilation. I wrote a simple use-case to show this. We probably need to do something like this: https://github.com/google/jax/issues/4269#issuecomment-691402423

But I am not sure how what's the best way to go here.

[quantshah]

Ok I will add the JIT tests in a separate PR. Everything looks good here. Will merge after the tests pass.