NimManager: show DVB-T2 / DVB-S2 in multi-type NIM selection

We used to show DVB-T / DVB-S, even if a NIM supported T2 / S2
This did not allow us to use NIM.isCompatible, because
though DVB-S is compatible with DVB-S2, DVB-S2 is not
necessarily compatible with DVB-S.