Add EventGrid CloudEvent templates to hard-coded list

We recently added new templates for the "EventGrid CloudEvent trigger" for .NET. This new template is already included with the template package version that is shipped with the latest Core Tools version. However, the template still does not show up in the list of new templates to create when you run `func new`. This is because Core Tools hardcodes a list of templates [here](https://github.com/Azure/azure-functions-core-tools/blob/1a61fc80af7aac1a1646e433fe2064784960d368/src/Azure.Functions.Cli/Helpers/DotnetHelpers.cs#L108) which it uses to list options after `func new`. As a result, we need to add the `EventGridCloudEventTrigger` template to this list. The templates were added [here](https://github.com/Azure/azure-functions-templates/pull/1438) and [here](https://github.com/Azure/azure-functions-templates/pull/1439).