benchmark against Kyber/drand TBLS

[omershlo]

https://github.com/drand/kyber/blob/master/sign/test/threshold.go#L14 TBLS is a threshold BLS written in Go, based on the same protocol, however I expect this library to be faster, mainly because we use the NIZK trick.

we should compare the signature (only signing, not dkg) generation time of the two implementations. Ideally in signatures per minute