fix(net): Clean up for mobile packets (#338)

### Breaking Change
- [X] `Mobile.GetOldPacketFlags()` no longer exists. Instead there is a flag for `Mobile.GetPacketFlags()`.

### Non-Breaking Changes
- [X] Consolidates move to world for mobiles
- [X] Consolidates mobile packets between stygian abyss and older

This PR supersedes changes in #337. That PR will need to be redone and broken out anyway.

Projects/Server/Network/Packets/IncomingPlayerPackets.cs

@@ -475,16 +475,9 @@ namespace Server.Network
                 return;
             }
 
-            if (state.StygianAbyss)
-            {
-                state.Send(new MobileUpdate(from));
-            }
-            else
-            {
-                state.Send(new MobileUpdateOld(from));
-            }
+            state.Send(new MobileUpdate(from, state.StygianAbyss));
 
-            state.Send(MobileIncoming.Create(state, from, from));
+            state.Send(new MobileIncoming(state, from, from));
 
             from.SendEverything();