Only tick entity tracker if players are tracking or if at entity ticking

Vanilla will only tick if the entity moves or is at entity ticking
level. For Paper, I am concerned that using exact Vanilla behavior
may cause problems with plugins - so we will settle on ticking the
tracker as well if players are tracking the entity.

This should reduce ticking for larger VD settings.

src/main/java/ca/spottedleaf/moonrise/mixin/entity_tracker/ChunkMapMixin.java

@@ -2,6 +2,7 @@
 
 import ca.spottedleaf.moonrise.common.list.ReferenceList;
 import ca.spottedleaf.moonrise.common.misc.NearbyPlayers;
+import ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity;
 import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
 import ca.spottedleaf.moonrise.patches.chunk_system.level.entity.server.ServerEntityLookup;
 import ca.spottedleaf.moonrise.patches.entity_tracker.EntityTrackerEntity;
@@ -10,6 +11,7 @@
 import com.mojang.datafixers.DataFixer;
 import net.minecraft.server.level.ChunkHolder;
 import net.minecraft.server.level.ChunkMap;
+import net.minecraft.server.level.FullChunkStatus;
 import net.minecraft.server.level.GeneratingChunkMap;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.entity.Entity;
@@ -77,7 +79,10 @@ private boolean newTrackerTick(final Iterator<?> iterator) {
                 continue;
             }
             ((EntityTrackerTrackedEntity)tracker).moonrise$tick(nearbyPlayers.getChunk(entity.chunkPosition()));
-            tracker.serverEntity.sendChanges();
+            if (((EntityTrackerTrackedEntity)tracker).moonrise$hasPlayers()
+                || ((ChunkSystemEntity)entity).moonrise$getChunkStatus().isOrAfter(FullChunkStatus.ENTITY_TICKING)) {
+                tracker.serverEntity.sendChanges();
+            }
         }
 
         return false;

src/main/java/ca/spottedleaf/moonrise/mixin/entity_tracker/TrackedEntityMixin.java

@@ -104,4 +104,9 @@ abstract class TrackedEntityMixin implements EntityTrackerTrackedEntity {
             this.removePlayer(player);
         }
     }
+
+    @Override
+    public final boolean moonrise$hasPlayers() {
+        return !this.seenBy.isEmpty();
+    }
 }

src/main/java/ca/spottedleaf/moonrise/patches/entity_tracker/EntityTrackerTrackedEntity.java

@@ -10,4 +10,6 @@ public interface EntityTrackerTrackedEntity {
 
     public void moonrise$clearPlayers();
 
+    public boolean moonrise$hasPlayers();
+
 }