added session context and implemented the executor interface for session

source/orm/sql/statement.cpp

@@ -98,4 +98,14 @@ void statement::reset() const
 std::string statement::sql() const {
   return statement_proxy_->sql();
 }
+
+utils::result<std::unique_ptr<query_result_impl>, utils::error> statement::fetch_internal() const {
+  auto result = statement_proxy_->fetch(*bindings_);
+  if (!result.is_ok()) {
+    return utils::failure(result.err());
+  }
+
+  //  logger_.info(statement_->query_.sql);
+  return result;
+}
 }