Add async_method_call to utility

Adding async_method_call in dbus utility gives us a place where we can
intercept method call requests from dbus to potentially add
logging/caching.

An example of logging is in the later commit:
https://gerrit.openbmc.org/c/openbmc/bmcweb/+/78265/

We already do this for setProperty, this moves the method calls to
follow a similar pattern.

Tested: Redfish service validator passes.

Change-Id: I6d2c96e2b6b6a023ed2138106a55faebca161592
Signed-off-by: Ed Tanous <etanous@nvidia.com>
diff --git a/include/async_resolve.hpp b/include/async_resolve.hpp
index 1a6f1b7..9dc41f7 100644
--- a/include/async_resolve.hpp
+++ b/include/async_resolve.hpp
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 // SPDX-FileCopyrightText: Copyright OpenBMC Authors
 #pragma once
-#include "dbus_singleton.hpp"
+#include "dbus_utility.hpp"
 #include "logging.hpp"
 
 #include <sys/socket.h>
@@ -90,7 +90,7 @@
         }
 
         uint64_t flag = 0;
-        crow::connections::systemBus->async_method_call(
+        dbus::utility::async_method_call(
             [host{std::string(host)}, portNum,
              handler = std::forward<ResolveHandler>(handler)](
                 const boost::system::error_code& ec,