Use EIP155 keyed transactor from go-ethereum

After bumping up go-ethereum dependency we can use keyed transactor with
chain ID implementation provided by the library instead of implementing
it on our own.

Author: pdyraga

tools/generators/ethlike/contract.go.tmpl

@@ -57,27 +57,12 @@ func New{{.Class}}(
 		From: accountKey.Address,
 	}
 
-	// FIXME Switch to bind.NewKeyedTransactorWithChainID when go-ethereum dep
-	// FIXME bumps beyond 1.9.25.
-	key := accountKey.PrivateKey
-	keyAddress := crypto.PubkeyToAddress(key.PublicKey)
-	if chainId == nil {
-		return nil, fmt.Errorf("no chain id specified")
-	}
-	transactorOptions := &bind.TransactOpts{
-		From: keyAddress,
-		Signer: func(_ types.Signer, address common.Address, tx *types.Transaction) (*types.Transaction, error) {
-			signer := types.NewEIP155Signer(chainId)
-
-			if address != keyAddress {
-				return nil, fmt.Errorf("not authorized to sign this account")
-			}
-			signature, err := crypto.Sign(signer.Hash(tx).Bytes(), key)
-			if err != nil {
-				return nil, err
-			}
-			return tx.WithSignature(signer, signature)
-		},
+	transactorOptions, err := bind.NewKeyedTransactorWithChainID(
+		accountKey.PrivateKey,
+		chainId,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("failed to instantiate transactor: [%v]", err)
 	}
 
 	contract, err := abi.New{{.AbiClass}}(

tools/generators/ethlike/contract_template_content.go

@@ -60,27 +60,12 @@ func New{{.Class}}(
 		From: accountKey.Address,
 	}
 
-	// FIXME Switch to bind.NewKeyedTransactorWithChainID when go-ethereum dep
-	// FIXME bumps beyond 1.9.25.
-	key := accountKey.PrivateKey
-	keyAddress := crypto.PubkeyToAddress(key.PublicKey)
-	if chainId == nil {
-		return nil, fmt.Errorf("no chain id specified")
-	}
-	transactorOptions := &bind.TransactOpts{
-		From: keyAddress,
-		Signer: func(_ types.Signer, address common.Address, tx *types.Transaction) (*types.Transaction, error) {
-			signer := types.NewEIP155Signer(chainId)
-
-			if address != keyAddress {
-				return nil, fmt.Errorf("not authorized to sign this account")
-			}
-			signature, err := crypto.Sign(signer.Hash(tx).Bytes(), key)
-			if err != nil {
-				return nil, err
-			}
-			return tx.WithSignature(signer, signature)
-		},
+	transactorOptions, err := bind.NewKeyedTransactorWithChainID(
+		accountKey.PrivateKey,
+		chainId,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("failed to instantiate transactor: [%v]", err)
 	}
 
 	contract, err := abi.New{{.AbiClass}}(