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/Serialization/BufferWriter.cs

@@ -286,6 +286,9 @@ namespace Server
             _buffer[Index++] = *(byte*)&value; // up to 30% faster to dereference the raw value on the stack
         }
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public void Write(Serial serial) => Write(serial.Value);
+
         internal void InternalWriteString(string value)
         {
             var remaining = m_Encoding.GetByteCount(value);