Upgrade VRF to be post-quantum secure

## Expected

As described on the Algorand website, the VRF implementation is expected to be updated to be post-quantum ready at some point before quantum computers threaten the security of the current implementation.
## Status

Algorand's current VRF implementation is based on a draft version of RFC 9381 and hasn't been updated in some years.

## Solution

The website suggests ZKB++ and XMSS are possible candidates for the replacement of the current VRF implementation. More recently, however, [this paper](https://eprint.iacr.org/2022/993.pdf) proposes another quantum-secure VRF protocol that compares favourably to the above and includes detailed discussion on how it can be applied to Algorand in particular.

The paper also includes a [reference implementation](https://gitlab.com/raykzhao/ivrf) in C with a zero-clause BSD license. The code could be ported to Go or used directly if it is appropriate to adapt into Algorand as-is.