fix(core): Removes implicit cast between Serial and uint (#728)

* Fixes spellbooks using serial ctor
* Fixes misc items where someone thought they had an amount and it didn't
* Fixes all `Food` types.

Projects/Server.Tests/Helpers/PacketWriter.cs

@@ -137,6 +137,8 @@ namespace Server.Network
             UnderlyingStream.Write(m_Buffer, 0, 4);
         }
 
+        public void Write(Serial serial) => Write(serial.Value);
+
         /// <summary>
         ///     Writes a sequence of bytes to the underlying stream
         /// </summary>