SPIGOT-4753: Add Pose API

By: md_5 <git@md-5.net>

paper-api/src/main/java/org/bukkit/event/entity/EntityPoseChangeEvent.java

@@ -0,0 +1,44 @@
+package org.bukkit.event.entity;
+
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Pose;
+import org.bukkit.event.HandlerList;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Called when an entity changes its pose.
+ *
+ * @see Entity#getPose()
+ */
+public class EntityPoseChangeEvent extends EntityEvent {
+
+    private static final HandlerList handlers = new HandlerList();
+    //
+    private final Pose pose;
+
+    public EntityPoseChangeEvent(@NotNull Entity who, @NotNull Pose pose) {
+        super(who);
+        this.pose = pose;
+    }
+
+    /**
+     * Gets the entity's new pose.
+     *
+     * @return the new pose
+     */
+    @NotNull
+    public Pose getPose() {
+        return pose;
+    }
+
+    @NotNull
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    @NotNull
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+}