Use ReadOnlyMemory<byte> for binary data to eliminate UTF-16 transcoding (#1070)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
Co-authored-by: ericstj <8918108+ericstj@users.noreply.github.com>
Co-authored-by: Eric StJohn <ericstj@microsoft.com>

samples/EverythingServer/Resources/SimpleResourceType.cs

@@ -1,6 +1,7 @@
 using ModelContextProtocol.Protocol;
 using ModelContextProtocol.Server;
 using System.ComponentModel;
+using System.Text;
 
 namespace EverythingServer.Resources;
 
@@ -31,7 +32,7 @@ public class SimpleResourceType
             } :
             new BlobResourceContents
             {
-                Blob = resource.Description!,
+                Blob = Encoding.UTF8.GetBytes(resource.Description!),
                 MimeType = resource.MimeType,
                 Uri = resource.Uri,
             };