Use Roslyn interceptors feature in config binder generator

[layomia]

ref: @captainsafia's work on the request delegate source generator - dotnet/aspnetcore#48817.

cc @tarekgh @eerhardt @ericstj.

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Issue Details

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ref: @captainsafia's work on the request delegate source generator - dotnet/aspnetcore#48817.

cc @tarekgh @eerhardt @ericstj.

Author:	layomia
Assignees:	layomia
Labels:	blocking-release, area-Extensions-Configuration
Milestone:	8.0.0

[layomia]

Can take this opportunity to fix #86363.

[layomia]

@tarekgh @ericstj @eiriktsarpalis looks like the interceptors feature requires <Features>$(Features);InterceptorsPreview</Features> in consuming projects. While the feature is in preview, it seems we should update the SDK to set it if EnableConfigurationBindingGenerator is set. Otherwise users would need to set two properties to use the generator.

The Web SDK already sets the feature property when binding & RDG generates are enabled, so the concern is about regular SDK scenarios.

[tarekgh]

@layomia does the interceptor feature will be released the same way? I mean users have to opt-in to get it. Or is this temporary for preview and will change when it gets released?

[layomia]

Yes I believe interceptors will be shipped as a preview feature in GA. cc @captainsafia.

[ericstj]

We can do the same thing as RDG here. Just add us to this condition:
https://github.com/dotnet/sdk/blob/b3b5a2800d4de997572068332bf222e2e8f808d5/src/WebSdk/ProjectSystem/Targets/Microsoft.NET.Sdk.Web.ProjectSystem.targets#L62-L65

We could do the same in our nuget package targets:
https://github.com/dotnet/runtime/blob/main/src/libraries/Microsoft.Extensions.Configuration.Binder/src/buildTransitive/Microsoft.Extensions.Configuration.Binder.targets

Might be good to have a safeguard in the generator just in case someone manages to invoke it without setting that property. I suspect RDG needs the same as well (eg Web class library that get's referenced by a normal app or class library).