Implement fee payment mechanism for gateway interactions on ZEVM

[lumtis]

We have mechanism to pay for the fees directly on the smart contract level:

• protocol-contracts/contracts/zevm/ZRC20.sol

  Line 257 in 161a0d4

  (address gasZRC20, uint256 gasFee) = withdrawGasFee();

We should port a similar mechanism to the v2 design.

This eventually requires to reuse the existing system contract (maybe consider renaming it) to store the address of the ZRC20 for gas tokens