Rework Async Chunks API in prep for merge, add utility

This adds a new Future based, Consumer<Chunk> based, and ability
to control whether or not to generate to the Async Chunk API.

Until Async Chunks merges, these API's are still synchronous, but
this commit will allow plugins to start using the API's in use
with the Async Chunks beta.

Spigot-Server-Patches/Add-async-chunk-load-API.patch

@@ -5,7 +5,7 @@ Subject: [PATCH] Add async chunk load API
 
 
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
-index e4c4cdb980..af977b171a 100644
+index e4c4cdb980..c2aa3917bf 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 @@ -0,0 +0,0 @@ public class CraftWorld implements World {
@@ -13,23 +13,14 @@ index e4c4cdb980..af977b171a 100644
      }
  
 +    // Paper start - Async chunk load API
-+    public void getChunkAtAsync(final int x, final int z, final ChunkLoadCallback callback) {
++    @Override
++    public java.util.concurrent.CompletableFuture<Chunk> getChunkAtAsync(final int x, final int z, final boolean gen) {
 +        final ChunkProviderServer cps = this.world.getChunkProviderServer();
-+        callback.onLoad(cps.getChunkAt(x, z, true, true).bukkitChunk); // TODO: Add back async variant
-+        /*cps.getChunkAt(x, z, new Runnable() {
-+            @Override
-+            public void run() {
-+                callback.onLoad(cps.getChunkAt(x, z).bukkitChunk);
-+            }
-+        });*/
-+    }
-+
-+    public void getChunkAtAsync(Block block, ChunkLoadCallback callback) {
-+        getChunkAtAsync(block.getX() >> 4, block.getZ() >> 4, callback);
-+    }
-+
-+    public void getChunkAtAsync(Location location, ChunkLoadCallback callback) {
-+        getChunkAtAsync(location.getBlockX() >> 4, location.getBlockZ() >> 4, callback);
++        java.util.concurrent.CompletableFuture<Chunk> future = new java.util.concurrent.CompletableFuture<>();
++        net.minecraft.server.Chunk chunk = cps.getChunkAt(x, z, true, gen);
++        // TODO: Add back async variant
++        future.complete(chunk != null ? chunk.bukkitChunk : null);
++        return future;
 +    }
 +    // Paper end
 +

Spigot-Server-Patches/Ignore-Dead-Entities-in-entityList-iteration.patch

@@ -71,7 +71,7 @@ index 597169b4cc..b18ea7154f 100644
              if (entity instanceof EntityInsentient) {
                  EntityInsentient entityinsentient = (EntityInsentient) entity;
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
-index af977b171a..80fd49b6e1 100644
+index c2aa3917bf..edf2e39e3d 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 @@ -0,0 +0,0 @@ public class CraftWorld implements World {

Spigot-Server-Patches/Implement-Force-Loaded-Chunk-API.patch

@@ -40,7 +40,7 @@ index 12c6d850d2..55394e0c15 100644
          Arrays.fill(emptySkyLight, (byte) 0xFF);
      }
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
-index 1ccf2a7609..755d2632fd 100644
+index 99d8199996..f8ef782f14 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 @@ -0,0 +0,0 @@ public class CraftWorld implements World {

Spigot-Server-Patches/Make-CraftWorld-loadChunk-int-int-false-load-unconve.patch

@@ -6,7 +6,7 @@ Subject: [PATCH] Make CraftWorld#loadChunk(int, int, false) load unconverted
 
 
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
-index 585a0c7fd2..b38e394f83 100644
+index b411776c3c..262363999d 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 @@ -0,0 +0,0 @@ public class CraftWorld implements World {

Spigot-Server-Patches/Optimize-getChunkIfLoaded-type-calls.patch

@@ -55,7 +55,7 @@ index 2ff8536d59..0c42d042b1 100644
              return chunk != null && !chunk.isEmpty();
          }
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
-index 755d2632fd..585a0c7fd2 100644
+index f8ef782f14..b411776c3c 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 @@ -0,0 +0,0 @@ public class CraftWorld implements World {

Spigot-Server-Patches/Send-nearby-packets-from-world-player-list-not-serve.patch

@@ -119,7 +119,7 @@ index 911d03c70b..f837e6c36c 100644
          }
  
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
-index 80fd49b6e1..ba2e768594 100644
+index edf2e39e3d..2611971575 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 @@ -0,0 +0,0 @@ public class CraftWorld implements World {

Spigot-Server-Patches/isChunkGenerated-API.patch

@@ -6,7 +6,7 @@ Subject: [PATCH] isChunkGenerated API
 Resolves #1329
 
 diff --git a/src/main/java/net/minecraft/server/ChunkProviderServer.java b/src/main/java/net/minecraft/server/ChunkProviderServer.java
-index 0ca071b879..96d49b469a 100644
+index 60f249a031..fc621911e0 100644
 --- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
 +++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
 @@ -0,0 +0,0 @@ public class ChunkProviderServer implements IChunkProvider {
@@ -20,7 +20,7 @@ index 0ca071b879..96d49b469a 100644
      public final Long2ObjectMap<Chunk> chunks = Long2ObjectMaps.synchronize(new ChunkMap(8192));
      private Chunk lastChunk;
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
-index ba2e768594..1ccf2a7609 100644
+index 2611971575..99d8199996 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 @@ -0,0 +0,0 @@ public class CraftWorld implements World {