Make UDC v2 backward compatible

[ericnordelo]

🧐 Motivation
In the UDC v2 we introduced a couple of breaking changes to make the standard easier to follow and more gas efficient. To avoid to much friction for tooling and contracts using v1, since v2 is not adopted yet, we should consider making these changes BC.

📝 Details
We had a unique param in v1 both received in the deploy_contract function and emitted in the ContractDeployed event. This was refactored to a from_zero field, which is semantically the negation of unique (since unique was meant to signalize when the deployment is not from the zero address). This can potentially be refactored into a semantically compatible name, that is more adequate than unique, like from_not_zero