u288 struct + calldata refactors

[feltroidprime]

Fixes #182
Notable changes :

• Cairo/Scarb updated to 2.8.2.

src/src

definitions.cairo

• Adds a u288 struct that holds 3 u96 limbs + impl Serde for it.
• Make E12D struct generic on <T> (in practice T=u384 or u288) + impl Serde for T=u288 & 384.
• Made G2Line struct also dependent on T. (Serde not needed as those are hardcoded)
• Made MillerLoopResultScalingFactor also dependent on T.
• Implement the corelib::num::traits::One & Zero for u384 & u288
• Implement the corelib::num::traits::One for E12D<u384> and E12D<u288>
• Implement corelib::num::traits::Zero for G1Point to represent the point at infinity. Removes the G1PointInfinity struct.
• Removes the E12DDefinitions trait (replaced by the num traits)
• Moves the E12D.conjugate method of the E12DDefinitions trait to a function in groth16.cairo

ec_ops.cairo

• Use the Zero trait instead of G1PointInfinity

Splitted utils.cairo into utils/hashing.cairo and utils/neg_3.cairo

hashing.cairo

• Added functions to hash based on u384 or u288.

pairing_check.cairo

• Update MPCheckHint structs to depend on u288 (bn) or u384 (bls)
• Update mpcheck_2P_2F functions to work with the updates in definitions.cairo & hashing.cairo

groth16.cairo

• Update mpcheck_3P_2F functions to work with the updates in definitions.cairo & hashing.cairo

core/circuit.cairo

• Add a next_u288 method for circuit_inputs.

hydra

• Adaptations to circuit compiler to support u288 and u288 related generic structs.
• Adaptations to groth16 generators to support u288.
• Groth16 calldata is now serialized as pure felt252 array instead of structs. The signature of groth16 contracts is now simply

fn verify_groth16_proof_bn254(
            ref self: ContractState, full_proof_with_hints: Span<felt252>,
        ) -> bool { 

• get_pairing_check_inputin multi_pairing_check.py generates input that looks like bls signature instead of previously ((P, Q), (-P, Q)) . This changes the tests for 2P_2F cases in pairing_test.cairo, as the previous hint content was sparse and not realistic.

src/contracts

• Groth16 contracts examples re-generated following the mentioned changes (using make rewrite)

BN254 groth16 now takes 9% less steps to verify thx to this, uses less calldata, and contracts uses a bit less bytecode.