ff 0.13 (#269)

* Partial move to ff 0.13

It turns out the newly released k256 0.12 isn't on ff 0.13, preventing further
work at this time.

* Update all crates to work on ff 0.13

The provided curves still need to be expanded to fit the new API.

* Finish adding dalek-ff-group ff 0.13 constants

* Correct FieldElement::product definition

Also stops exporting macros.

* Test most new parts of ff 0.13

* Additionally test ff-group-tests with BLS12-381 and the pasta curves

We only tested curves from RustCrypto. Now we test a curve offered by zk-crypto,
the group behind ff/group, and the pasta curves, which is by Zcash (though
Zcash developers are also behind zk-crypto).

* Finish Ed448

Fully specifies all constants, passes all tests in ff-group-tests, and finishes moving to ff-0.13.

* Add RustCrypto/elliptic-curves to allowed git repos

Needed due to k256/p256 incorrectly defining product.

* Finish writing ff 0.13 tests

* Add additional comments to dalek

* Further comments

* Update ethereum-serai to ff 0.13

crypto/frost/src/curve/mod.rs

@@ -92,7 +92,7 @@ pub trait Curve: Ciphersuite {
     while {
       seed.extend(repr.as_ref());
       res = Zeroizing::new(<Self as Curve>::hash_to_F(b"nonce", seed.deref()));
-      res.ct_eq(&Self::F::zero()).into()
+      res.ct_eq(&Self::F::ZERO).into()
     } {
       seed = Zeroizing::new(vec![0; 32]);
       rng.fill_bytes(&mut seed);