Console Unify API Changes (#3059)

* Remove unused IChatCommand.

* Lots of refactoring into a shared context.

* Removed ICommonSession from server concmd Execute.

* Added argStr parameter to concmd execute.

* The execute function of client concmds now returns void, use the new shell.RemoteExecuteCommand function to forward commands.

* Finally move shells and commands into shared.

* Console commands can now be registered directly without a class in a shared context.

* Engine API Changes.

* Repair rebase damage.

* Update Submodule.

Content.Server/Interfaces/Chat/IChatCommand.cs

@@ -1,10 +0,0 @@
-using Robust.Shared.Console;
-using Robust.Shared.Interfaces.Network;
-
-namespace Content.Server.Interfaces.Chat
-{
-    public interface IChatCommand : ICommand
-    {
-        void Execute(IChatManager manager, INetChannel client, params string[] args);
-    }
-}