Make compatible with ITensors 0.9

[JoeyT1994]

The latest version of ITensors (v0.9) contained some breaking changes due to the use of TensorOperations in optimal_contraction_sequence. This PR updates ITensorNetworks.jl to be compatible with those changes, with belief propagation and apply directly making use of optimal_sequence finding.

[mtfishman]

@JoeyT1994 it looks like you'll need to resolve conflicts caused by the removal of ITensorMPS.jl as a dependency.

[lkdvos]

It looks like something is blocking the update of StridedViews to v0.4. This doesn't really change functionality, but it (massively) cuts down the compilation times of TensorOperations. It might pay off to see what is holding that back.

[mtfishman]

It looks like something is blocking the update of StridedViews to v0.4. This doesn't really change functionality, but it (massively) cuts down the compilation times of TensorOperations. It might pay off to see what is holding that back.

Thanks for the heads up, I need to update the compat entry for StridedViews in NDTensors, looking into that now.

[mtfishman]

Should be fixed once ITensor/ITensors.jl#1633 is merged and registered.