eth: move eth.Config to a common package (#22205)

This moves the eth config definition into a separate package, eth/ethconfig. 
Packages eth and les can now import this common package instead of
importing eth from les, reducing dependencies.

Co-authored-by: Felix Lange <fjl@twurst.com>

graphql/graphql_test.go

@@ -28,6 +28,7 @@ import (
 	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/eth/ethconfig"
 	"github.com/ethereum/go-ethereum/node"
 	"github.com/ethereum/go-ethereum/params"
 
@@ -191,7 +192,7 @@ func createNode(t *testing.T, gqlEnabled bool) *node.Node {
 
 func createGQLService(t *testing.T, stack *node.Node) {
 	// create backend
-	ethConf := &eth.Config{
+	ethConf := &ethconfig.Config{
 		Genesis: &core.Genesis{
 			Config:     params.AllEthashProtocolChanges,
 			GasLimit:   11500000,