Current Chunk for Entity and Block Entities, counts by entity type

This enables us a fast reference to the entities current chunk instead
of having to look it up by hashmap lookups.

We also store counts by type to further enable other performance optimizations in later patches.

Spigot-Server-Patches/Don-t-let-fishinghooks-use-portals.patch

@@ -5,10 +5,10 @@ Subject: [PATCH] Don't let fishinghooks use portals
 
 
 diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
-index 9ab892876..42da707ae 100644
+index c675a6e16..f71528b5f 100644
 --- a/src/main/java/net/minecraft/server/Entity.java
 +++ b/src/main/java/net/minecraft/server/Entity.java
-@@ -0,0 +0,0 @@ public abstract class Entity implements ICommandListener {
+@@ -0,0 +0,0 @@ public abstract class Entity implements ICommandListener, KeyedObject { // Paper
      public boolean ah;
      public boolean impulse;
      public int portalCooldown;