feat: Validium Mode

[mationorato]

🌟 Feature Request

Modify the Executor.sol contract to be able to be compiled either in Validium mode or in Rollup mode.

📝 Description

Use solpp to decide if you want to compile the contracts in Validium or rollup mode using the --validium-mode flag on zk init .

The lines that depend on pubdata should be compiled only when zk init command is run without the --validium-mode flag (Rollup mode).