Constant dusk_blindbid::BID_HASHING_TYPE_FIELDS

pub const BID_HASHING_TYPE_FIELDS: [u8; 32];

Following the guidelines for Poseidon Hashing proving statements generation given in https://hackmd.io/@7dpNYqjKQGeYC7wMlPxHtQ/BkfS78Y9L, we export the field types const which will be needed by the gadgets that want to implement the hash of a Bid inside of a Circuit.