[ENHANCEMENT] blocks(::PermutedDimsArray) should return NestedPermutedDimsArray

[mtfishman]

Redesign blocks(::PermutedDimsArray) so that it returns a NestedPermutedDimsArray.

[mtfishman]

Note that that NestedPermutedDimsArray will have to be added as a supported wrapper of SparseArraysBase.AbstractSparseArray. That should be done through a package extension of SparseArraysBase.jl. The logic for overloading the SparseArraysBase.jl interface for Base wrappers is here: https://github.com/ITensor/SparseArraysBase.jl/blob/c67b83a1348d74a6e6bdafa977740e923da0dd6e/src/wrappers.jl. Ideally that code would be made extensible by defining something like a WrappedAbstractSparseArrayInterface in the style of Derive.jl, so then it would only require a few overloads and all of the functionality of SparseArraysBase.jl can be derived for the new NestedPermutedDimsArray wrapper. One subtle part with that plan that we'll have to work out is making sure that NestedPermutedDimsArray can interoperate with other wrapper types.