Random cleanups to users of Level.OVERWORLD and reduce minecraft_server usage (#1697)

- Use `overworld()` instead of `getLevel(Level.OVERWORLD)` when convenient
- Remove now unnecessary `// OW` comments, from when it had no mappings
- Make spawn chunk size and light batches not depend on global server instance
- Merge all spawn chunk size logic into SpawnChunks instead of methods in the validator
- Remove unneeded `withWorld(OVERWORLD)` with just-created server `CommandSource`s
- Use enhanced for in light batch application

src/main/java/carpet/utils/Messenger.java

@@ -1,7 +1,6 @@
 package carpet.utils;
 
 import net.minecraft.ChatFormatting;
-import net.minecraft.Util;
 import net.minecraft.commands.CommandSourceStack;
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.chat.Component;
@@ -13,7 +12,6 @@ import net.minecraft.network.chat.TextColor;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.world.entity.MobCategory;
 import net.minecraft.world.entity.player.Player;
-import net.minecraft.world.level.Level;
 import net.minecraft.world.phys.Vec3;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -162,7 +160,7 @@ public class Messenger
     }
     public static Component tp(String desc, int x, int y, int z)
     {
-        return getCoordsTextComponent(desc, (float)x, (float)y, (float)z, true);
+        return getCoordsTextComponent(desc, x, y, z, true);
     }
 
     /// to be continued
@@ -233,7 +231,7 @@ public class Messenger
     public static void m(CommandSourceStack source, Object ... fields)
     {
         if (source != null)
-            source.sendSuccess(Messenger.c(fields),source.getServer() != null && source.getServer().getLevel(Level.OVERWORLD) != null); //OW
+            source.sendSuccess(Messenger.c(fields), source.getServer() != null && source.getServer().overworld() != null);
     }
     public static void m(Player player, Object ... fields)
     {

src/main/java/carpet/utils/SpawnChunks.java

@@ -1,15 +1,21 @@
 package carpet.utils;
 
 import carpet.fakes.ChunkTicketManagerInterface;
+import net.minecraft.core.BlockPos;
 import net.minecraft.server.level.DistanceManager;
-import net.minecraft.server.level.ServerChunkCache;
+import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.level.ChunkPos;
 
 public class SpawnChunks
 {
-    public static void changeSpawnChunks(ServerChunkCache chunkManager, ChunkPos pos, int size)
+    public static void changeSpawnSize(ServerLevel overworld, int size)
     {
-        DistanceManager ticketManager = chunkManager.chunkMap.getDistanceManager();
-        ((ChunkTicketManagerInterface)ticketManager).changeSpawnChunks(pos, size);
+        ChunkPos centerChunk = new ChunkPos(new BlockPos(
+                overworld.getLevelData().getXSpawn(),
+                overworld.getLevelData().getYSpawn(),
+                overworld.getLevelData().getZSpawn()
+        ));
+        DistanceManager ticketManager = overworld.getChunkSource().chunkMap.getDistanceManager();
+        ((ChunkTicketManagerInterface)ticketManager).changeSpawnChunks(centerChunk, size);
     }
 }