Add entity liquid API

== AT ==
public net.minecraft.world.entity.Entity isInRain()Z
public net.minecraft.world.entity.Entity isInBubbleColumn()Z

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java

@@ -1021,4 +1021,41 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
         return getHandle().spawnReason;
     }
     // Paper end - entity spawn reason API
+
+    // Paper start - entity liquid API
+    @Override
+    public boolean isUnderWater() {
+        return getHandle().isUnderWater();
+    }
+
+    @Override
+    public boolean isInRain() {
+        return getHandle().isInRain();
+    }
+
+    @Override
+    public boolean isInBubbleColumn() {
+        return getHandle().isInBubbleColumn();
+    }
+
+    @Override
+    public boolean isInWaterOrRain() {
+        return getHandle().isInWaterOrRain();
+    }
+
+    @Override
+    public boolean isInWaterOrBubbleColumn() {
+        return getHandle().isInWaterOrBubble();
+    }
+
+    @Override
+    public boolean isInWaterOrRainOrBubbleColumn() {
+        return getHandle().isInWaterRainOrBubble();
+    }
+
+    @Override
+    public boolean isInLava() {
+        return getHandle().isInLava();
+    }
+    // Paper end - entity liquid API
 }