fix(core): Converts boat packets (#416)

- [X] Converts boat packets
- [X] Makes a packet container builder for packet 0xF7
- [X] Generalizes world item packet so it works for mobiles too

Notes:
- This PR doesn't address proper smooth movement for boats.

Projects/Server.Tests/Tests/Network/Packets/Utilities/PacketTestUtilities.cs

@@ -1,28 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Net.Sockets;
-using Moq;
-using Server.Network;
-
-namespace Server.Tests.Network
-{
-    public static class PacketTestUtilities
-    {
-        public static Span<byte> Compile(this Packet p) =>
-            p.Compile(false, out var length).AsSpan(0, length);
-
-        public static NetState CreateTestNetState()
-        {
-            var socket = new Mock<ISocket>();
-            socket
-                .Setup(s => s.SendAsync(It.IsAny<IList<ArraySegment<byte>>>(), SocketFlags.None))
-                .ReturnsAsync(() => 0);
-
-            socket
-                .Setup(s => s.ReceiveAsync(It.IsAny<IList<ArraySegment<byte>>>(), SocketFlags.None))
-                .ReturnsAsync(() => 0);
-
-            return new NetState(socket.Object);
-        }
-    }
-}