Backend agnostic implementation of quantum Hamiltonian generation

[king-p3nguin]

• Resolve #161
• Add script to benchmark sparse hamiltonian building

(I am contributing to this project as a unitaryHACK participant)

[refraction-ray]

thanks for the nice contribution. could you also include an example script in /examples to both check the correctness and compare the efficiency of the sparse Hamiltonian generation for different backends? (say generate Hamiltonian for several typical systems in O(20) qubits). I can also utilize the same script to benchmark the efficiency between previous impl. and the current one in case any performance degradation.

[king-p3nguin]

I noticed that examples/hamiltonian_building.py does the benchmark for the numpy backend, so I also added the jax and tensorflow backends in the script.

[refraction-ray]

LGTM, I have further added jit for these functions to improve the efficiency

[refraction-ray]

@all-contributors please add @king-p3nguin for example

[allcontributors[bot]]

@refraction-ray

I've put up a pull request to add @king-p3nguin! :tada: