Big Rock: Filters for Razor Pages

[rynowak]

Pages should use basically the same filter types as controllers, but should expose some unique functionality in place of action filters. In general a pages developer will want to accomplish the same kinds of things with filters as a controller/action developer.

This includes:

• authorization (authZ filters)
• middleware-like behavior (resource filters)
• scoped exception handling (exception filters)
• decorating the execution of results (result filters)
• manipulating action arguments (action filters)

We'll want to provide a little something extra for pages, likely to do with manipulating handler methods 👍

There's a lot more to do here, because designing a new filter type, we need to decide how filters get configured when you have a mix of pages/page-models/handler-methods/application-model.

Related items:

• Add a filter provider for TempDataAttribute to RazorPages  #5979 Add a filter provider for TempDataAttribute to RazorPages
• Support Filters for RazorPages #6124 Support Filters for RazorPages
• Add a new filter type for pages #6331 Add a new filter type for pages
• Add logging and diagnostic source for page handlers #6332 Add logging and diagnostic source for page handlers
• Improve unit tests for PageActionInvoker #6333 Improve unit tests for PageActionInvoker
• Rationalize what happens when you have filter attributes on a page model or handler method #6334 Rationalize filters as attributes with Pages

[rynowak]

Everything in this list is done or in PR, so closing this issue.