fix: productName with utf8 characters cause dmg icon position error

Close #1234

Author: changkun

packages/electron-builder/templates/dmg/dmgProperties.pl

@@ -4,6 +4,7 @@
 use Mac::Memory qw( );
 use Mac::Files qw( NewAliasMinimal );
 use Encode ();
+use utf8;
 
 my($backgroundWidth, $backgroundHeight);
 
@@ -69,4 +70,4 @@ sub syscall_setfinderinfo {
   my($r) = syscall(SYS_setattrlist, $path, $bits, $data, length($data), 0);
   die "setattrlist($path): $!\n"
       if $r == -1;
-}
+}