Function ndarray_einsum_beta::slow_versions::slow_einsum_given_sized_contraction

pub fn slow_einsum_given_sized_contraction<A: LinalgScalar>(
    sized_contraction: &SizedContraction, 
    operands: &[&dyn ArrayLike<A>]
) -> ArrayD<A>

Very inefficient and explicit to be removed or only used for testing

Iterates through all possible combinations of index values and executes thousands of times slower than real implementation.