Grant temporary immunity to hopper minecarts while actively pulling (fixes #8281) (#8282)

Reduce the impact from EAR on hopper minecart based unloaders by making them immune to
EAR while pulling objects. The EAR is still active outside misc activation range when
the hopper minecart is idle, keeping lag low.

patches/server/0349-Entity-Activation-Range-2.0.patch

@@ -302,6 +302,44 @@ index f957c0aca36b7228ac3a33ca04c948b1d10642d1..39fc94b1e1555fd6706391223dd27831
  
          super.customServerAiStep();
      }
+diff --git a/src/main/java/net/minecraft/world/entity/vehicle/MinecartHopper.java b/src/main/java/net/minecraft/world/entity/vehicle/MinecartHopper.java
+index 540c23f6297c34cf8e7bf8312ceaa5fc868f414c..2866385a64b22b7dc82b6122c62bcea6b0908a60 100644
+--- a/src/main/java/net/minecraft/world/entity/vehicle/MinecartHopper.java
++++ b/src/main/java/net/minecraft/world/entity/vehicle/MinecartHopper.java
+@@ -57,6 +57,7 @@ public class MinecartHopper extends AbstractMinecartContainer implements Hopper
+         if (bl != this.isEnabled()) {
+             this.setEnabled(bl);
+         }
++        this.immunize();  // Paper
+ 
+     }
+ 
+@@ -107,11 +108,13 @@ public class MinecartHopper extends AbstractMinecartContainer implements Hopper
+ 
+     public boolean suckInItems() {
+         if (HopperBlockEntity.suckInItems(this.level, this)) {
++            this.immunize();  // Paper
+             return true;
+         } else {
+             List<ItemEntity> list = this.level.getEntitiesOfClass(ItemEntity.class, this.getBoundingBox().inflate(0.25D, 0.0D, 0.25D), EntitySelector.ENTITY_STILL_ALIVE);
+             if (!list.isEmpty()) {
+                 HopperBlockEntity.addItem(this, list.get(0));
++                this.immunize();  // Paper
+             }
+ 
+             return false;
+@@ -149,4 +152,11 @@ public class MinecartHopper extends AbstractMinecartContainer implements Hopper
+     public AbstractContainerMenu createMenu(int syncId, Inventory playerInventory) {
+         return new HopperMenu(syncId, playerInventory, this);
+     }
++
++    // Paper start
++    public void immunize() {
++        this.activatedImmunityTick = Math.max(this.activatedImmunityTick, net.minecraft.server.MinecraftServer.currentTick + 20);
++    }
++    // Paper end
++
+ }
 diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
 index e6bfc9cdf116b2233a638eec369a80eb8536aa18..4c1d34bd274d8e2a4003a286536652367da9488a 100644
 --- a/src/main/java/net/minecraft/world/level/Level.java