### Summary
* Added World.NewVirtual for creating virtual serial numbers
* Reserved range 0x7EEEEEEE to 0x7FFFFFFF for virtual serials
* Hair and Facial hair (for mobiles) now use virtual serials instead of FakeSerial() functions
* Consolidated virtual hair to a single `VirtualHairInfo` class.
Corpse hair and facial hair now persists across save/load and hair and facial hair no longer teleport to newest corpse.
## Breaking Changes
Incoming packet registration signature has changed to:
```cs
delegate* void OnReceiveCallback(NetState state, SpanReader reader, int packetLength);
IncomingPackets.Register(int packetID, int length, bool ingame, OnReceiveCallback onReceive);
```
For example, an incoming packet handler signature would now look like this:
```cs
public static void SomeIncomingPacket(NetState state, SpanReader reader, int packetLength)
{
// Parse the data
}
```
## Summary
Updates the network Pipe class to use a mirrored memory technique. This technique involves mapping the same physical memory to two contiguous virtual memory spaces so the byte buffer appears duplicated. This allows writing to a double-sized array to wrap around without the need for the `CircularBuffer` classes.
In practice this allows us to use `Span<byte>` as if the buffer was a regular array.
### Bug Fixes
- [X] Fixes bad fixed length string parsing
