fix(core): Converts BB packets (#406)

- [X] Organizes and splits up bulletin boards
- [X] Converts packets

Projects/Server/Network/PacketUtilities.cs

@@ -40,6 +40,12 @@ namespace Server.Network
             writer.Seek(0, SeekOrigin.End);
         }
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static Span<T> SliceToLength<T>(this Span<T> span, int length) => span.Slice(0, length);
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static ReadOnlySpan<T> SliceToLength<T>(this ReadOnlySpan<T> span, int length) => span.Slice(0, length);
+
         // If LOCAL INIT is off, then stack/heap allocations have garbage data
         // Initializes the first byte (Packet ID) so it can be used as a flag.
         [MethodImpl(MethodImplOptions.AggressiveInlining)]