* Simpler Keccak pseudo-permutation
After rejecting a value, I think it's a little simpler to continue the hash chain vs retrying with an incremented nonce.
* PR feedback
* fix byte order
My goal is to make the FRI code independent of circuit objects like `CommonCircuitData`, so that it can be reused by STARK code which won't involve those objects.
A few changes here:
- Move `rate_bits` and `cap_height` into `FriConfig`.
- Move `degree_bits` into `FriParameters` (since it's instance size specific).
- Make `FriParams` contain `FriConfig`, so FRI methods can take just the former and access fields in both.
- Replace `CommonCircuitConfig` with `FriParams` in FRI prover methods.
The FRI verifier methods still involve circuit objects, as they have PLONK logic in `fri_combine_initial`. Will think about how to deal with that after this.
* Split into crates
I kept other changes to a minimum, so 95% of this is just moving things. One complication that came up is that since `PrimeField` is now outside the plonky2 crate, these two impls now conflict:
```
impl<F: PrimeField> From<HashOut<F>> for Vec<u8> { ... }
impl<F: PrimeField> From<HashOut<F>> for Vec<F> { ... }
```
with this note:
```
note: upstream crates may add a new impl of trait `plonky2_field::field_types::PrimeField` for type `u8` in future versions
```
I worked around this by adding a `GenericHashOut` trait with methods like `to_bytes()` instead of overloading `From`/`Into`. Personally I prefer the explicitness anyway.
* Move out permutation network stuff also
* Fix imports
* Fix import
* Also move out insertion
* Comment
* fmt
* PR feedback
* Print timing for a regular Poseidon recursive proof
Rather than the Keccak-256 proof. I kept it but hid the timing since it's less important to us. Alternatively we could test Keccak-256 only in the size-optimized test, since that's basically testing a bridge proof. Let me know if you have a preference.
* Remove Keccak proof per PR discussion
