Cleaned up interfaces. Extracted server state machine trigger handler to seperated classes. Removed legacy code

MoonlightServers.Daemon/ServerSystem/Handlers/ShutdownHandler.cs

@@ -0,0 +1,42 @@
+using MoonlightServers.Daemon.ServerSystem.Enums;
+using MoonlightServers.Daemon.ServerSystem.Interfaces;
+using MoonlightServers.Daemon.ServerSystem.Models;
+using Stateless;
+
+namespace MoonlightServers.Daemon.ServerSystem.Handlers;
+
+public class ShutdownHandler : IServerStateHandler
+{
+    private readonly ServerContext ServerContext;
+
+    public ShutdownHandler(ServerContext serverContext)
+    {
+        ServerContext = serverContext;
+    }
+
+    public async Task ExecuteAsync(StateMachine<ServerState, ServerTrigger>.Transition transition)
+    {
+        // Filter (we only want to handle exists from the runtime, so we filter out the installing state)
+        if (transition is
+            {
+                Destination: ServerState.Offline,
+                Source: not ServerState.Installing,
+                Trigger: ServerTrigger.Exited
+            })
+            return;
+
+        // Plan:
+        // 1. Handle possible crash
+        // 2. Remove runtime
+
+        // 1. Handle possible crash
+        // TODO: Handle crash here
+
+        // 2. Remove runtime
+
+        await ServerContext.Server.Runtime.DestroyAsync();
+    }
+
+    public ValueTask DisposeAsync()
+        => ValueTask.CompletedTask;
+}