[Blazor webview] Exception handling for blazor webview

[javiercn]

We have several issues that touch different aspects of the same area:

#3695
#2057
#2598

Since these aspects are deeply related, this issue supersedes the other mentioned issues and provides some details on the expected behaviors:

• Unhandled exceptions on a Blazor Webview should be treated in the same way as unhandled exceptions in other platforms.
  • Raising up to the "AppDomain" "UnhandledException" event in Winforms and WPF before terminating the application.
  • Using the same mechanism Maui offers for dealing unhandled exceptions.
• We should consider a "standard" way to display errors across platforms to aid in development scenarios. One option here is to use the Details and Summary html elements to provide additional details during development. This would follow the same pattern we use in other platforms via the DETAILEDERRORS config value.

General expectations around exception types:

• Un-awaited task throws:
  • These should unwind the stack and be handled at the platform level. Blazor doesn't have any insight into these exceptions and can't react to them.
• Render exception:
  • These flow up to Renderer.HandleException where they need to get rethrown for the general exception handling mechanism from the platform to kick in.
• Event handler exception: These are handled by Blazor in the same way across different platforms and already flow to Renderer.HandleException
• JSInterop exceptions: These should unwind the stack and be handled at the platform level.
• Exceptions while bootstrapping the Blazor Webview: These should unwind the stack and be handled at the platform level, for example, DI exceptions when failing to resolve a service.
• Caught exceptions within component code:
  • These are only visible through capturing first-chance exceptions in the debugger as Blazor doesn't get visibility into them (they are caught).
  • Our own components shouldn't contain any of these types of exceptions, however in general, these exceptions are not "flavor" specific and also affect Webassembly and desktop.

[TanayParikh]

Support has been added for WPF/WinForms and needs to be consumed by dotnet/maui, by consuming aspnetcore 6.0.4 packages.

For dotnet/MAUI there isn't a global exception management capability. I've created #5535 to track adding support for this.

[TanayParikh]

Pushing to RC3 as we're awaiting release of the 6.0.4 SDK which has the dotnet/aspnetcore#40765 fix.

[TanayParikh]

This is now working in maui main for WPF/WinForms. Closing this issue out, further efforts for first class MAUI support will be tracked via #5535.