Consider refactoring ScopeExtensions

[jamescrosswell]

We have some ScopeExtensions for ASP.NET Core that get [trigged by the SentryMiddleware](

sentry-dotnet/src/Sentry.AspNetCore/SentryMiddleware.cs

Line 258 in d1e5efc

scope.Populate(context, _options);

.

In classic ASP.NET apps, something similar (but not identical) happens in the SystemWebRequestEventProcessor.

Ideally both platforms would share some common logic so that fixes we applied to one would get applied to the other. Would need a bit of head scratching to come up with a way to do this since they pull their information from different contexts (and have different scope stack containers).

Originally posted by @jamescrosswell in #3337

[linear]

NET-446 Consider refactoring ScopeExtensions