[#1141] morph/client: Allow to use more integer types as arguments

Also, use `*big.Int` as integer value, see nspcc-dev/neo-go#2413.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

pkg/morph/client/client_test.go

@@ -1,6 +1,7 @@
 package client
 
 import (
+	"math/big"
 	"testing"
 
 	sc "github.com/nspcc-dev/neo-go/pkg/smartcontract"
@@ -20,6 +21,12 @@ func TestToStackParameter(t *testing.T) {
 		{
 			value:   int64(100),
 			expType: sc.IntegerType,
+			expVal:  big.NewInt(100),
+		},
+		{
+			value:   uint64(100),
+			expType: sc.IntegerType,
+			expVal:  big.NewInt(100),
 		},
 		{
 			value:   "hello world",