Refactor Extensions class and update project dependencies

- Comment out `protobuf-net` package reference in `Core.csproj` for potential future use.
- Add new `using` directives in `Extensions.cs` and remove `ProtoBuf` namespace, indicating a shift away from Protobuf serialization.
- Reintroduce and restructure previously removed methods in the `Extensions` class, with some methods commented out for reference.
- Update `GetPropertyValue` method to use `ArgumentNullException.ThrowIfNull` for .NET 6.0 compatibility while maintaining support for earlier versions.
- Comment out several serialization and XML handling methods, suggesting a potential deprecation or design shift.
- Overall, these changes enhance code clarity and maintain compatibility with newer frameworks.

Author: wforney

SharedCode.Core/Core.csproj

@@ -10,7 +10,7 @@
 			<PrivateAssets>all</PrivateAssets>
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 		</PackageReference>
-		<PackageReference Include="protobuf-net" />
+		<!--<PackageReference Include="protobuf-net" />-->
 		<PackageReference Include="System.Drawing.Common" />
 		<PackageReference Include="System.Reflection.Metadata" />
 		<PackageReference Include="System.Text.Json" />