Make KroneckerProductLazyTensor call each component's root decomposition

[wjmaddox]

For PSD tensors, we can write the root decomposition of a Kronecker product,
M = A \otimes B = LL' \otimes NN' = (L \otimes N)(L' \otimes N')
for general root decompositions rather than just the symeig case which is implemented currently.

This allows for faster and less memory intensive factorizations of very large Kronecker products as it gives the components the ability to use Lanczos.

Note: I also had to slightly modify the batched KP lazy tensor test case to get lanczos to converge here due to the repeated eigenvalue.