Add ability to load data from set list

[alexsb]

We should be able to load data of this form:

Set 1: A, B, C, D, E, F, G, H
Set 2: A, B, D, F, I, J, K, L
Set 3: A, H, J, M, N, O, P, Q
Set 4: B, L, O, P, R, S, T, U

Here, A, B, C, etc. are the items. We don't handle attributes in this case.

[kirangadhave]

This should be migrated to multinet now