Add EnterDungeonCmd, fix error when enter dungeon by changescene, import spawn cmd

src/main/java/emu/grasscutter/command/commands/EnterDungeonCommand.java

@@ -0,0 +1,42 @@
+package emu.grasscutter.command.commands;
+
+import emu.grasscutter.command.Command;
+import emu.grasscutter.command.CommandHandler;
+import emu.grasscutter.game.player.Player;
+
+import java.util.List;
+
+@Command(label = "enterdungeon", usage = "enterdungeon <dungeon id>",
+        description = "Enter a dungeon", aliases = {"dungeon"}, permission = "player.enterdungeon")
+public final class EnterDungeonCommand implements CommandHandler {
+    @Override
+    public void execute(Player sender, List<String> args) {
+        if (sender == null) {
+            CommandHandler.sendMessage(null, "Run this command in-game.");
+            return;
+        }
+
+        if (args.size() < 1) {
+            CommandHandler.sendMessage(sender, "Usage: enterdungeon <dungeon id>");
+            return;
+        }
+
+        try {
+            int dungeonId = Integer.parseInt(args.get(0));
+            
+            if (dungeonId == sender.getSceneId()) {
+            	CommandHandler.sendMessage(sender, "You are already in that dungeon");
+            	return;
+            }
+            
+            boolean result = sender.getServer().getDungeonManager().enterDungeon(sender.getSession().getPlayer(), 0, dungeonId);
+            CommandHandler.sendMessage(sender, "Changed to dungeon " + dungeonId);
+
+            if (!result) {
+                CommandHandler.sendMessage(sender, "Dungeon does not exist");
+            }
+        } catch (Exception e) {
+            CommandHandler.sendMessage(sender, "Usage: enterdungeon <dungeon id>");
+        }
+    }
+}