Cleanup MCUtils patch for chunk system

Remove utilities that are unused, as well as replacing
the full chunk map with a concurrentutil implementation.

Additionally, fix the addition/removal of chunks to/from the
full chunk map so that getChunkIfLoaded correctly returns a
non-null chunk when calling the load or unload events.

patches/server/0034-Expose-server-build-information.patch

@@ -472,7 +472,7 @@ index 0000000000000000000000000000000000000000..790bad0494454ca12ee152e3de6da3da
 +    }
 +}
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index 8fbc764fd2802f735b9d5fac2dabca6a7cebe58e..3d9c7105bfdb1b0c63a036ba3213d51b2fb6425f 100644
+index c09f3dc29c86fef9edfe7831776a77fc73e52210..6f5b04a59fa1173bfdea2c59a9c13ca3710abb0c 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
 @@ -43,7 +43,6 @@ import java.util.Set;
@@ -492,7 +492,7 @@ index 8fbc764fd2802f735b9d5fac2dabca6a7cebe58e..3d9c7105bfdb1b0c63a036ba3213d51b
  import org.bukkit.event.server.ServerLoadEvent;
  // CraftBukkit end
  
-@@ -1708,7 +1705,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+@@ -1703,7 +1700,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
  
      @DontObfuscate
      public String getServerModName() {