all: use uint256 in state (#28598)

This change makes use of uin256 to represent balance in state. It touches primarily upon statedb, stateobject and state processing, trying to avoid changes in transaction pools, core types, rpc and tracers.

graphql/graphql.go

@@ -100,7 +100,7 @@ func (a *Account) Balance(ctx context.Context) (hexutil.Big, error) {
 	if err != nil {
 		return hexutil.Big{}, err
 	}
-	balance := state.GetBalance(a.address)
+	balance := state.GetBalance(a.address).ToBig()
 	if balance == nil {
 		return hexutil.Big{}, fmt.Errorf("failed to load balance %x", a.address)
 	}