Fix MC-136995 - Chunk loading and unloading issue with entities placed in exact positions. (#5160)

This includes three commits from 1.12.x:
https://github.com/MinecraftForge/MinecraftForge/commit/c20a5e8805f64097430cf0722011f20862a8df9c
https://github.com/MinecraftForge/MinecraftForge/commit/93b704b459c6f537d3b1651008c49ce1db2e0ca1
https://github.com/MinecraftForge/MinecraftForge/commit/ee0d43bbde37e258c36de1003436dbe3fcf88077

Scatter gun patches to improve entity tracking and position tracking.
Provided by Aikar through the Paper project, this commit of patches combines the following patches:

https://github.com/PaperMC/Paper/blob/fd1bd5223a461b6d98280bb8f2d67280a30dd24a/Spigot-Server-Patches/0306-Mark-chunk-dirty-anytime-entities-change-to-guarante.patch
https://github.com/PaperMC/Paper/blob/fd1bd5223a461b6d98280bb8f2d67280a30dd24a/Spigot-Server-Patches/0315-Always-process-chunk-registration-after-moving.patch
https://github.com/PaperMC/Paper/blob/fd1bd5223a461b6d98280bb8f2d67280a30dd24a/Spigot-Server-Patches/0335-Ensure-chunks-are-always-loaded-on-hard-position-set.patch
https://github.com/PaperMC/Paper/blob/fd1bd5223a461b6d98280bb8f2d67280a30dd24a/Spigot-Server-Patches/0378-Sync-Player-Position-to-Vehicles.patch

Co-authored-by: Gabriel Harris-Rouquette <github@gabizou.com>

src/main/java/net/minecraftforge/common/extensions/IForgeEntity.java

@@ -181,4 +181,28 @@ public interface IForgeEntity extends ICapabilitySerializable<NBTTagCompound>
         if (forSpawnCount && (this instanceof EntityLiving) && ((EntityLiving)this).isNoDespawnRequired()) return false;
         return type.getBaseClass().isAssignableFrom(this.getClass());
     }
+
+    /**
+     * Gets whether this entity has been added to a world (for tracking). Specifically
+     * between the times when an entity is added to a world and the entity being removed
+     * from the world's tracked lists. See {@link World#onEntityAdded(Entity)} and
+     * {@link World#onEntityRemoved(Entity)}.
+     *
+     * @return True if this entity is being tracked by a world
+     */
+    boolean isAddedToWorld();
+
+    /**
+     * Called after the entity has been added to the world's
+     * ticking list. Can be overriden, but needs to call super
+     * to prevent MC-136995.
+     */
+    void onAddedToWorld();
+
+    /**
+     * Called after the entity has been removed to the world's
+     * ticking list. Can be overriden, but needs to call super
+     * to prevent MC-136995.
+     */
+    void onRemovedFromWorld();
 }