feat(ecc): using lookup

[chaosma]

• We can use lookup to reduce the scalar bits decomposition constraints. To do so, we need define a 2-bits table. This will cost one extra column. (need think about if we can re-use the 16 bits lookup table in BigNat optimization). This method will also makes poseidon gadget smaller.

[chaosma]

Reference code:

https://github.com/axiom-crypto/halo2-lib/blob/community-edition/halo2-ecc/src/ecc/mod.rs