Shared Containers (#1579)

* Added a basic server simulation framework for help with tests.

* Moved as much as possible to Robust.Shared/Containers.
Moved ContainerSlot from content to engine.

* Moved ClientContainer to shared.

* Merged client/server ContainerManagerComponents into a single shared version.

* ContainerManagerComponent is now implicitly registered with the attributes.

* Migrated to 2021 serialization technology.

* Existing Unit Tests work.

* More tests coverage.
Fixed bug with transferring items between containers.

* Container Type info is now sent over the network.

* Merge client/server container systems.

* Code cleanup.

* Attempted to fix dictionary serialization.
Logs warning when trying to check if an unknown GridId is paused.

* Remove OldCode.

Robust.Shared/Serialization/RobustSerializer.cs

@@ -1,9 +1,10 @@
-using NetSerializer;
+using NetSerializer;
 using Robust.Shared.IoC;
 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Reflection;
 using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Reflection;
@@ -182,6 +183,23 @@ namespace Robust.Shared.Serialization
         public bool CanSerialize(Type type)
             => _serializableTypes.Contains(type);
 
+        /// <inheritdoc />
+        public Type? FindSerializedType(Type assignableType, string serializedTypeName)
+        {
+            var types = _reflectionManager.GetAllChildren(assignableType);
+            foreach (var type in types)
+            {
+                var serializedAttribute = type.GetCustomAttribute<SerializedTypeAttribute>();
+
+                if(serializedAttribute is null)
+                    continue;
+
+                if (serializedAttribute.SerializeName == serializedTypeName)
+                    return type;
+            }
+
+            return null;
+        }
     }
 
 }