Research BLS library and binding

[riemannulus]

Context

For VRF and bulk proof of signing, we need the Boneh–Lynn–Shacham cryptography signature. But based on our distinct characteristic, using Unity as a wallet, we cannot use any library.

Rationale

We should choose 2 or 3 library for BLS and check libplanet compability.

Tasklist

• [x] #3595
• [x] #3603
• [x] #3596
• [x] #3597

[riemannulus]

We do not need BLS anymore. use ECDSA for VRF. Closed.