Add Phase Estimation to Ising sample(s) and organize them

[DmitryVasilevsky]

As noted in comments to PR #2060 we now have three samples that demonstrate Ising model.

1. https://github.com/microsoft/qsharp/blob/main/samples/estimation/Dynamics.qs (Large, can only be used for estimation)
2. https://github.com/microsoft/qsharp/blob/main/samples/estimation/estimation-ising-2D.ipynb (Notebook explaining the algorithm)
3. https://github.com/microsoft/qsharp/blob/main/samples/algorithms/SimpleIsing.qs (Simple, base profile compliant, can be used in simulation)

We need to consider reducing number of samples

We also need to consider adding Phase Estimation to actually find the eigenvalue and the ground state energy.

We may want to use 4th Order Trotterization formulas in Ising example.

Thanks @msoeken and @aarthims for suggestions!

[billti]

Don't see a immediate need for this. Closing for now. Will reopen if & when we decide to implement.