Fix to_i conversion for C++ that was changed in 0acd030

Fixes

[info] - cpp_stl:"12345".to_i *** FAILED ***
[info]   "[kaitai::kstream::string_to_int](std::string("12345"..." was not equal to "[std::stoi](std::string("12345"..." (TranslatorSpec.scala:520)
[info]   Analysis:
[info]   "[kaitai::kstream::string_to_int](std::string("12345"..." -> "[std::stoi](std::string("12345"..."
[info] - cpp_stl:"1234fe".to_i(16) *** FAILED ***
[info]   "[kaitai::kstream::string_to_int(std::string("1234fe")], 16)" was not equal to "[std::stoi(std::string("1234fe"), 0], 16)" (TranslatorSpec.scala:533)
[info]   Analysis:
[info]   "[kaitai::kstream::string_to_int(std::string("1234fe")], 16)" -> "[std::stoi(std::string("1234fe"), 0], 16)"

jvm/src/test/scala/io/kaitai/struct/translators/TranslatorSpec.scala

@@ -518,7 +518,7 @@ class TranslatorSpec extends AnyFunSuite {
     ))
 
   full("\"12345\".to_i", CalcIntType, CalcIntType, Map[LanguageCompilerStatic, String](
-    CppCompiler -> "std::stoi(std::string(\"12345\"))",
+    CppCompiler -> "kaitai::kstream::string_to_int(std::string(\"12345\"))",
     CSharpCompiler -> "Convert.ToInt64(\"12345\", 10)",
     GoCompiler -> "func()(int){i, err := strconv.Atoi(\"12345\"); if (err != nil) { panic(err) }; return i}()",
     JavaCompiler -> "Long.parseLong(\"12345\", 10)",
@@ -531,7 +531,7 @@ class TranslatorSpec extends AnyFunSuite {
   ))
 
   full("\"1234fe\".to_i(16)", CalcIntType, CalcIntType, Map[LanguageCompilerStatic, String](
-    CppCompiler -> "std::stoi(std::string(\"1234fe\"), 0, 16)",
+    CppCompiler -> "kaitai::kstream::string_to_int(std::string(\"1234fe\"), 16)",
     CSharpCompiler -> "Convert.ToInt64(\"1234fe\", 16)",
     GoCompiler -> "func()(int64){i, err := strconv.ParseInt(\"1234fe\", 16, 64); if (err != nil) { panic(err) }; return i}()",
     JavaCompiler -> "Long.parseLong(\"1234fe\", 16)",