Couple of things. You need to make sure that you install the Dialogs plugin into your project. You do this through the CLI:
phonegap plugin add cordova-plugin-dialogs
Once you have the plugin installed your code will work: I assume you have read - cordova-plugin-dialogs - Apache Cordova
I don't think you need to include this
<param name="ios-package" value="CDVNotification" />
in your config.xml. It might be auto added and managed by the CLI.
I also recommend loading cordova and related js files before any app files.