[2.0] Make Dependency Injection more magical

[cilerler]

As a user, I want Restier to integrate with ASP.NET Core's default Dependency Injection (DI) container, so that I can streamline project setup.

[robertmclaws]

Given that Restier is pretty dependent on OData's .NET implementation, which requires a DI container per route, this is not likely going to be possible in the current iteration.

If I had my way, I would redesign OData AspNetCore 9.0 to use the KeyedServices in .NET 8 to keep all of the services fully-accessible in the root DI container. Then I would build Restier 2.0 on top of that.

We'll see if I can convince Microsoft to do that. Until then, we might be able to make just Restier 2.0 work that way... we'll just have to see what happens.