useChain
 Hook for getting the Chain  object of the network that the user is connected - but only if
it's a supported network (added in the ThirdwebProvider 's supportedChains  or one of default chains
 Returns undefined  if the network is not supported or the user is not connected to a wallet. You can use the useConnectionStatus  hook to check if the user is connected to a wallet or not to differentiate between the two cases.
 If you only want to get the chain id of the network the user is connected to regardless of whether it's supported or not, use useChainId  instead.
 An object of type Chain  from @thirdweb-dev/chains  package containing various information about the network, or undefined  if the network is not supported or user is not connected to a wallet.