Fix infeasibility detection logic

[fabinsch]

we have a first check in our helper function global_primal_residual_infeasibility that returns if a problem is supposed to be feasible.

I think the logic we want to check is

inf_norm(dy) == 0 AND infty_norm(dz) == 0

in this case, the problem is feasible.

However, we negate this statement as the output of the function is used to set the variable called is_primal_infeasible, here.

If we negate the statement above, and should be replaced by OR. The fix I propose here solves the issue in #327 and proxqp returns PROXQP_PRIMAL_INFEASIBLE as expected.