🐛 `QuickExact` returns duplicate charge configurations about fiction

[wlambooy]

Much to your benefit, I found a 5 DB example with the same issue :)

TEST_CASE("QuickExact duplicate charge configurations", "[quickexact]")
{
    using sidb_lyt = sidb_cell_clk_lyt_siqad;
    sidb_lyt lyt{};

    lyt.assign_cell_type({2, 2, 1}, sidb_lyt::cell_type::NORMAL);
    lyt.assign_cell_type({2, 3, 0}, sidb_lyt::cell_type::NORMAL);
    lyt.assign_cell_type({7, 3, 1}, sidb_lyt::cell_type::NORMAL);
    lyt.assign_cell_type({7, 4, 0}, sidb_lyt::cell_type::NORMAL);
    lyt.assign_cell_type({8, 4, 1}, sidb_lyt::cell_type::NORMAL);


    const sidb_simulation_result<sidb_lyt>& qe_res = quickexact(lyt);

    // QuickExact returns 3 physically valid charge distributions in total
    REQUIRE(qe_res.charge_distributions.size() == 3);
    
    // This loop asserts that the first two are equal
    for (uint64_t i = 0; i < 2; ++i)
    {
        CHECK(qe_res.charge_distributions[i].get_charge_state({2, 2, 1}) == sidb_charge_state::NEGATIVE);
        CHECK(qe_res.charge_distributions[i].get_charge_state({2, 3, 0}) == sidb_charge_state::NEUTRAL);
        CHECK(qe_res.charge_distributions[i].get_charge_state({7, 3, 1}) == sidb_charge_state::NEGATIVE);
        CHECK(qe_res.charge_distributions[i].get_charge_state({7, 4, 0}) == sidb_charge_state::POSITIVE);
        CHECK(qe_res.charge_distributions[i].get_charge_state({8, 4, 1}) == sidb_charge_state::NEGATIVE);
    }
}