Ensure we keep metadata for fields

[MichalStrehovsky]

We already do this for methods but FieldMetadataNode was missing the matching logic (we'd only keep metadata for custom modifiers in the lines above those I'm touching).

[Copilot]

Pull Request Overview

This PR adds logic to preserve metadata for fields by updating dependency analysis and provides a corresponding test to validate the behavior.

• Added a test in Reflection.cs to verify field and parameter metadata is preserved.
• Updated FieldMetadataNode.cs to include metadata for the field type.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/tests/nativeaot/SmokeTests/Reflection/Reflection.cs	Added TestFieldAndParamMetadata to verify field and parameter type metadata preservation.
src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/FieldMetadataNode.cs	Updated dependency analysis to include the field's type metadata.

[Copilot]

The declaration 'public class FieldType;' appears to be incomplete; in C# class declarations require a body (e.g., use '{ }' instead of a semicolon).

Suggested change

	public class FieldType;
	public class FieldType { }

[Copilot]

The declaration 'public class ParameterType;' is incomplete and should include a body (e.g., '{ }') to be valid C# syntax.

Suggested change

	public class ParameterType;
	public class ParameterType { }