feat(protocol-contracts): add modularity to deploy protocol contracts script

[zmalatrax]

Add arguments to the script to select the network on which the ZamaOFT contract can be deployed.
Prior version was locked to deploying on arbitrum-testnet (Arbitrum Sepolia).

Proposed version allow the user to deploy on a network off a list (currently arbitrum-testnet or gateway-testnet), to limit risk of deploying to the wrong network.
Once deployed, the ZamaOFTAdapter and ZamaOFT contracts must be wired, based on the LayerZero config file, which can now be provided by the user, if multiple config files exist for the different supported networks ; It defaults to layerzero.config.ts

Note: It also adds the RPC_URL_ARBITRUM_SEPOLIA variable to the .env.example, as the hardhat.config.ts is already configured to use this value if provided