feat: op consumer chain slashing (2/2)

[parketh]

Summary

This is a follow-on PR from #92 (implement slashing for op stack consumer chains)

It updates the EquivocationEvidence msg to match the latest Babylon update

Test plan

# build the contract
cargo build
cargo optimize

# test it
cargo test
cargo integration

[SebastianElvis]

Not sure if this is necessary 😓

[parketh]

i followed the same struct definition as in babylon node. do you mean we should remove the alias here?

[SebastianElvis]

Yep I was suggesting to remove it as there are many Bytes definitions in various libraries already. No strong objection though