Task: Use TaskEvent messages

Task registry messages make more sense to use
for task events then standard registry entries
when applicable. Use them.

Tested:

    "Messages": [
        {
            "@odata.type": "#Message.v1_0_0.Message",
            "Message": "The task with id 0 has started.",
            "MessageArgs": [
                "0"
            ],
            "MessageId": "TaskEvent.1.0.1.TaskStarted",
            "Resolution": "None.",
            "Severity": "OK"
        }
    ],

Validator passed

Change-Id: I707492544e18def2833e8a2e2216ce803c42c775
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/redfish-core/lib/task.hpp b/redfish-core/lib/task.hpp
index 2f86a6a..cbae67b 100644
--- a/redfish-core/lib/task.hpp
+++ b/redfish-core/lib/task.hpp
@@ -20,6 +20,7 @@
 #include <boost/asio.hpp>
 #include <boost/container/flat_map.hpp>
 #include <chrono>
+#include <task_messages.hpp>
 #include <variant>
 
 namespace redfish
@@ -206,9 +207,11 @@
                 self->finishTask();
                 self->state = "Cancelled";
                 self->status = "Warning";
-                self->messages.emplace_back(messages::internalError());
+                self->messages.emplace_back(
+                    messages::taskAborted(std::to_string(self->index)));
                 self->callback(ec, msg, self);
             });
+        messages.emplace_back(messages::taskStarted(std::to_string(index)));
     }
 
     std::function<bool(boost::system::error_code, sdbusplus::message::message &,