Initial Client/Server Communication

#1
Followed the MagicOnion quickstart guide, borrowing code from the chat sample app to get something working

Assets/Scripts/MagicOnion.Abstractions/ServerStreamingResult.cs

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+using Grpc.Core;
+using MessagePack;
+using System;
+using System.Threading.Tasks;
+
+namespace MagicOnion
+{
+    /// <summary>
+    /// Wrapped AsyncServerStreamingCall.
+    /// </summary>
+    public struct ServerStreamingResult<TResponse> : IDisposable
+    {
+        readonly AsyncServerStreamingCall<byte[]> inner;
+        readonly IAsyncStreamReader<TResponse> responseStream;
+
+        public ServerStreamingResult(AsyncServerStreamingCall<byte[]> inner, IAsyncStreamReader<TResponse> responseStream, MessagePackSerializerOptions serializerOptions)
+        {
+            this.inner = inner;
+            this.responseStream = responseStream;
+        }
+
+        /// <summary>
+        /// Async stream to read streaming responses.
+        /// </summary>
+        public IAsyncStreamReader<TResponse> ResponseStream
+        {
+            get
+            {
+                return responseStream;
+            }
+        }
+
+        /// <summary>
+        /// Asynchronous access to response headers.
+        /// </summary>
+        public Task<Metadata> ResponseHeadersAsync
+        {
+            get
+            {
+                return this.inner.ResponseHeadersAsync;
+            }
+        }
+
+        /// <summary>
+        /// Gets the call status if the call has already finished.
+        /// Throws InvalidOperationException otherwise.
+        /// </summary>
+        public Status GetStatus()
+        {
+            return this.inner.GetStatus();
+        }
+
+        /// <summary>
+        /// Gets the call trailing metadata if the call has already finished.
+        /// Throws InvalidOperationException otherwise.
+        /// </summary>
+        public Metadata GetTrailers()
+        {
+            return this.inner.GetTrailers();
+        }
+
+        /// <summary>
+        /// Provides means to cleanup after the call.
+        /// If the call has already finished normally (response stream has been fully read), doesn't do anything.
+        /// Otherwise, requests cancellation of the call which should terminate all pending async operations associated with the call.
+        /// As a result, all resources being used by the call should be released eventually.
+        /// </summary>
+        /// <remarks>
+        /// Normally, there is no need for you to dispose the call unless you want to utilize the
+        /// "Cancel" semantics of invoking <c>Dispose</c>.
+        /// </remarks>
+        public void Dispose()
+        {
+            if (this.inner != null)
+            {
+                this.inner.Dispose();
+            }
+        }
+    }
+}