Add support for verifying beacons with the G1-G2 swap

[AnomalRoil]

Once drand/drand#1103 lands, and we've launched a new testnet network with the swapped curves for the BLS signature, we should make sure to add support for verifying these beacons.

The Noble library currently doesn't support it, but it should have all the required methods to implement it easily now that hash to curve is supported on both groups:
paulmillr/noble-bls12-381#43

[CluEleSsUK]

as-is this is fixed, though we have a new swapped scheme which will be fixed when #68 is merged