ethereum, ethclient: add FeeHistory support (#25403)

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

ethclient/ethclient_test.go

@@ -508,6 +508,29 @@ func testStatusFunctions(t *testing.T, client *rpc.Client) {
 	if gasTipCap.Cmp(big.NewInt(234375000)) != 0 {
 		t.Fatalf("unexpected gas tip cap: %v", gasTipCap)
 	}
+
+	// FeeHistory
+	history, err := ec.FeeHistory(context.Background(), 1, big.NewInt(2), []float64{95, 99})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	want := &ethereum.FeeHistory{
+		OldestBlock: big.NewInt(2),
+		Reward: [][]*big.Int{
+			{
+				big.NewInt(234375000),
+				big.NewInt(234375000),
+			},
+		},
+		BaseFee: []*big.Int{
+			big.NewInt(765625000),
+			big.NewInt(671627818),
+		},
+		GasUsedRatio: []float64{0.008912678667376286},
+	}
+	if !reflect.DeepEqual(history, want) {
+		t.Fatalf("FeeHistory result doesn't match expected: (got: %v, want: %v)", history, want)
+	}
 }
 
 func testCallContractAtHash(t *testing.T, client *rpc.Client) {