Fix NativeAOT delegate commands by preserving reflection metadata

[dusrdev]

Before this PR:

When using delegate handlers such as:

var app = ConsoleApp.Create();
app.Add("", Commands.Root);

and Commands.Root included attributes like ValidationAttributes, the generated code would still call command.Method.GetParameters() even after source generation, This requires metadata that may be trimmed when compiling with Native AOT, causing a runtime exception.

What this PR does:

1. Adds a sample console app "NativeAotTrimming" under tests that reproduces the error when compiled with Native AOT.
2. Adds a unit test that publishes (compiles) said app with Native AOT, then runs it as a process to check the exit code (if the MethodInfo was trimmed away - exit code != 0 and test fails.
3. Updates Emitter to fix the issue

• Defines a SymbolDisplayFormat to fully qualify type names.
• If command.CommandMethodInfo is null, meaning the runtime will rely on reflection to discover the delegate’s parameters, the emitter now uses the handler’s IMethodSymbol to create a DynamicDependency attribute that points to the handler’s containing type.
• Injects this attribute before the RunCommand method signature.
• If CommandMethodInfo is not null, no changes are made.

Rationale:

This change ensures that the necessary MethodInfo is preserved when it would otherwise be trimmed.

An alternative approach would be to cache the method and its parameters during build time, but that would require significant refactoring of Emitter. The current solution fixes the issue for affected users, and caching could be explored as a potential improvement in the future.

[neuecc]

Thank you!
I definitely want to support this, but since the target is just a single method, instead of DynamicallyAccessedMemberTypes, how about specifying it like this:

            var docId = dynamicDependencyMethod.GetDocumentationCommentId();
            var parametersPart = docId!.Substring(docId.IndexOf('('));
            var memberSignature = dynamicDependencyMethod.Name + parametersPart;

            var containingType = dynamicDependencyMethod.ContainingType.ToDisplayString(DynamicDependencyContainingTypeFormat);
            dynamicDependencyAttribute = $"[global::System.Diagnostics.CodeAnalysis.DynamicDependency(\"{memberSignature}\", typeof({containingType}))]";

[dusrdev]

Thanks, using GetDocumentationCommentId is actually cleaner and allowed me to also remove the static field.

[neuecc]

thank you!

[dusrdev]

My pleasure.

@neuecc Considering the scope of its use, I think I could improve PooledStringWriter, clean up the code a bit and also gain some perf, would you want me to tackle this next?

[neuecc]

PooledStringWriter is unused code so no need to care.(I've just removed unused code in master branch)