I see that the Azure IoT Suite mentions Azure Web Apps, but I can't seem to find any documentation or source which might explain/implement a web app.
Is there a standard pattern for developing a web-based application (e.g., Core MVC App) around the Azure IoT resources?
Not sure what you mean by "standard pattern" however if you're looking for a head start, the source code for both Azure IoT Suite solutions (Predictive Maintenance and Remote Monitoring) is available on GitHub.