* Add BN254 and Grumpkin Poseidon configurations

* Remove unncecessary comment

* Fix BN254 Poseidon config test

* Correction

* Update folding-schemes/src/transcript/poseidon/grumpkin.rs

Co-authored-by: Pierre <pdaixmoreux@gmail.com>

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Co-authored-by: Pierre <pdaixmoreux@gmail.com>

* circom: add external_inputs

* adapt new external_inputs interface to the FoldingScheme trait and Nova impl

* adapt examples to new FCircuit external_inputs interface

* add state_len & external_inputs_len params to CircomFCircuit

* add examples/circom_full_flow.rs

* merge the params initializer functions, clippy

* circom: move r1cs reading to FCircuit::new instead of each step

* CI/examples: add circom so it can run the circom_full_flow example

* expose params & structs for external usage

* add full_flow example, move examples into 'examples' dir

* Add external inputs logic to F function/circuit. Add an example of usage with external inputs too.

* Add examples run into CI