Cleanup & Fixes for .NET 5 (#309)

- [X] Fixes several bugs
- [X] Updates more ordinal issues
- [X] Cleans up the code a bit
- [X] Turns classes static that should have been
- [X] Changes TcpServer.Instances to a HashSet

Bumps release version

Projects/Server.Tests/Tests/Network/Packets/Outgoing/CombatPacketTests.cs

@@ -21,9 +21,7 @@ namespace Server.Tests.Network
             AssertThat.Equal(result.Buffer[0].AsSpan(0), expected);
         }
 
-        [Theory]
-        [InlineData(true)]
-        [InlineData(false)]
+        [Theory, InlineData(true), InlineData(false)]
         public void TestSetWarMode(bool warmode)
         {
             var expected = new SetWarMode(warmode).Compile();