Update Event Hubs templates for new .NET types in 5.0.0 extension

[mattchenderson]

The .NET Event Hubs templates use EventData. The namespace for the SDK is different when using the 5.0.0 extension, as has the shape of some of the properties used by the template (e.g., Body) . See https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-event-hubs-trigger?tabs=csharp#usage

This affects:

• https://github.com/Azure/azure-functions-templates/blob/dev/Functions.Templates/Templates/EventHubTrigger-CSharp/EventHubTriggerCSharp.cs
• https://github.com/Azure/azure-functions-templates/blob/dev/Functions.Templates/Templates/EventHubTrigger-CSharp/EventHubTriggerCSharp.csx
• https://github.com/Azure/azure-functions-templates/blob/dev/Functions.Templates/Templates/EventHubTrigger-FSharp/EventHubTriggerFSharp.fs

It should also affect the associated templating files so that the updated package references are used (extension and underlying Azure SDK).

[mattchenderson]

The templating file work is tracked separately in https://github.com/Azure/azure-functions-templates/issues/1114 but is tied in with this item.

[fabiocav]

@AnatoliB would you be able to have this assigned? @soninaren would be able to provide assistance here if needed.