Investigate whether we can use the same grand product relations parameters for all instances

[maramihali]

[maramihali]

after discussions with the theory team, the outcome is that we have to fold relation parameters as well (because otherwise the protocol changes); @codygunton is working on implementing this

additionally, the signature of combiner changes here as relation parameters are taken from each instance: https://github.com/AztecProtocol/aztec-packages/blob/master/barretenberg/cpp/src/barretenberg/honk/proof_system/protogalaxy_prover.hpp#L219

[maramihali]

closed by AztecProtocol/aztec-packages#2935