VSTHRD200 should be able to have method type configured

Is your feature request related to a problem? Please describe.

This analyzer reports all instances of this condition. There are different schools of thought about requiring an Async suffix on awaitable methods.

• Always, all the time (or not at all) -- these are the only current options
• Only on public methods
• Only on methods that also have non-awaitable methods
• Only on non-private methods (my preference)
• Combinations of the above

Describe the solution you'd like

I'd like to see .editorconfig settings to modify the behavior of this analyzer.
dotnet_diagnostic.VSTHRD200.allowed_exceptions = private, internal, protected, no_non_async

Whether it takes this exact form doesn't matter. I just want to shut this warning up for private methods.

Describe alternatives you've considered

I can silence all instances of this analyzer, silence it by file, live with warnings, or follow rules that we don't agree with.

Additional context

I use source generators for binding methods to a view, and the "fix" functionality renames methods but not the generated reference to them in XAML. So this:

private async Task AddStation() { }

which is generated as

public global::CommunityToolkit.Mvvm.Input.IRelayCommand DeleteUserCommand => deleteUserCommand ??= new global::CommunityToolkit.Mvvm.Input.RelayCommand(new global::System.Action(DeleteUser), () => CanDeleteUser);

would be DeleteUserAsyncCommand, and I would have to go through all of my XAML views and fix it.

Start at the VSTHRD200 analyzer entry point and inspect how its current all-or-nothing behavior is implemented. Define the supported method-type combinations and their .editorconfig representation, then verify that private-method exceptions and the existing behavior are covered by the analyzer's tests.