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/redfish-core/lib/systems.hpp b/redfish-core/lib/systems.hpp
index 45400dd..d7aeed9 100644
--- a/redfish-core/lib/systems.hpp
+++ b/redfish-core/lib/systems.hpp
@@ -2843,7 +2843,8 @@
         "xyz.openbmc_project.Control.Host.NMI";
     constexpr const char* method = "NMI";
 
-    crow::connections::systemBus->async_method_call(
+    dbus::utility::async_method_call(
+        asyncResp,
         [asyncResp](const boost::system::error_code& ec) {
             if (ec)
             {