Move the new AddResourceConfiguration to the Abstractions project

[MikeAlhayek]

No description provided.

[Piedone]

I contemplated putting this there (together with the .Core project) but it's not actually an abstraction: it's neither an interface nor a fundamental concrete type, but a concrete implementation that needs to be like this only because ResourceManager uses ResourceManagementOptions like this. Solely from ResourceManagementOptions it doesn't follow that we should have this registration (and still, it's not an abstraction).

[MikeAlhayek]

I don't see an issue with placing it in the abstraction. The ResourceManagement is part of the abstraction, so to implement a new resource management, you'll need the abstractions only. So it does not make sense to include other project just to use that extension. I think it's fair to put it in the abstraction project so people don't need to include yet another library. If we move it to core, they would have to switch from using Abstractions to Core.

[Piedone]

OK, just be sure to revert the csproj changes under https://github.com/OrchardCMS/OrchardCore/pull/17095/files and feel free to merge.