Operations related to WethBridge needs to be removed from the zksync-web3-sdk

We will not deploy WethBridge in CronosV2 because the CronosV2 will be using CRO as native token, not ETH

We can deal with WETH the same way we are dealing with any ERC20 (Using the ERC20Bridge)

Thus all operations to WethBridge can be removed from the sdk