Test backend graph calculation logic with smart contract tests

[kelemeno]

We can do this, as we test the backend by requiring the SC. So if we run the SC tests as a script, we can also test the backend.

[kelemeno]

*re-querying .

Expanding on this: we test the backend graph management by calculating the new graph, and requerying the SC, and comparing the results. This calculation, requerying happens after the SC processes some txs. We can run complicated, or multiple txs. We can do this simply, by running scripts. What scripts to run? Well the tests can be run as scripts.