core/vm: adds refund as part of the json standard trace (#17910)

This adds the global accumulated refund counter to the standard
json output as a numeric json value. Previously this was not very
interesting since it was not used much, but with the new sstore
gas changes the value is a lot more interesting from a consensus
investigation perspective.

core/vm/logger_test.go

@@ -21,6 +21,7 @@ import (
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/params"
 )
 
@@ -41,9 +42,15 @@ func (d *dummyContractRef) SetBalance(*big.Int)        {}
 func (d *dummyContractRef) SetNonce(uint64)            {}
 func (d *dummyContractRef) Balance() *big.Int          { return new(big.Int) }
 
+type dummyStatedb struct {
+	state.StateDB
+}
+
+func (dummyStatedb) GetRefund() uint64 { return 1337 }
+
 func TestStoreCapture(t *testing.T) {
 	var (
-		env      = NewEVM(Context{}, nil, params.TestChainConfig, Config{})
+		env      = NewEVM(Context{}, &dummyStatedb{}, params.TestChainConfig, Config{})
 		logger   = NewStructLogger(nil)
 		mem      = NewMemory()
 		stack    = newstack()
@@ -51,9 +58,7 @@ func TestStoreCapture(t *testing.T) {
 	)
 	stack.push(big.NewInt(1))
 	stack.push(big.NewInt(0))
-
 	var index common.Hash
-
 	logger.CaptureState(env, 0, SSTORE, 0, 0, mem, stack, contract, 0, nil)
 	if len(logger.changedValues[contract.Address()]) == 0 {
 		t.Fatalf("expected exactly 1 changed value on address %x, got %d", contract.Address(), len(logger.changedValues[contract.Address()]))