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

coins/monero/src/wallet/send/multisig.rs

@@ -148,7 +148,7 @@ impl SignableTransaction {
       let clsag = ClsagMultisig::new(transcript.clone(), input.key(), inputs[i].clone());
       key_images.push((
         clsag.H,
-        keys.current_offset().unwrap_or_else(dfg::Scalar::zero).0 + self.inputs[i].key_offset(),
+        keys.current_offset().unwrap_or(dfg::Scalar::ZERO).0 + self.inputs[i].key_offset(),
       ));
       clsags.push(AlgorithmMachine::new(clsag, offset));
     }