peltool: Add Notes from message registry file

Add the Notes section found in the message registry file to the json
output (if it's present and not empty).

Example:

"Error Details": {
    "Message":  "Unknown (Original event not in message registry)",
    "Notes": [
                "This is used when the actual error name isn't",
                "found in the registry."
    ]
}

Signed-off-by: Harisuddin Mohamed Isa <harisuddin@gmail.com>
Change-Id: I69773547c06f6361055c2f0decd07967d0012946
diff --git a/extensions/openpower-pels/src.cpp b/extensions/openpower-pels/src.cpp
index 19d140d..7e764bb 100644
--- a/extensions/openpower-pels/src.cpp
+++ b/extensions/openpower-pels/src.cpp
@@ -503,6 +503,10 @@
                     jsonInsert(errorOut, "Message", errorMsg.value(), 2);
                 }
             }
+            if (entry->doc.notes)
+            {
+                jsonInsertArray(errorOut, "Notes", entry->doc.notes.value(), 2);
+            }
             if (entry->src.hexwordADFields)
             {
                 std::map<size_t, std::tuple<std::string, std::string>>