Expose Endpoint Name as a read-only property on EndpointConfiguration

[danielmarbach]

This pull request exposes the endpoint name as a get-only property on the EndpointConfiguration.

While the endpoint name can already be retrieved using:

endpointConfiguration.GetSettings().EndpointName()

providing direct access through the configuration offers additional value and improves usability.

Motivation

1. Improved support for multi-hosting scenarios
   Exposing the endpoint name as a property allows the EndpointConfiguration to serve as the sole information carrier. This is particularly useful when the endpoint name is used as an identifier for keyed services.

2. Enhanced developer experience
   Accessing the endpoint name directly is more intuitive, discoverable, and expressive than retrieving it through settings.

3. Simplified integrations
   This change streamlines registrations and bindings for the new Functions integration, reducing complexity and boilerplate.

[danielmarbach]

I looked at the internal usage of the endpoint name and concluded it is not useful to try to use the property directly because Core internals never use EndpointConfiguration directly, and it seems excessive and not useful trying to change that.

[andreasohlund]

Shared == "input queue" right?

[DavidBoike]

I took it as not-the-instance-specific-with-discriminator one but I don't know what you call that with better words. 😉