SPIGOT-759: Add FireworkExplodeEvent.

By: DemonWav <demonwav@gmail.com>

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

@@ -0,0 +1,49 @@
+package org.bukkit.event.entity;
+
+import org.bukkit.entity.Firework;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+
+/**
+ * Called when a firework explodes.
+ */
+public class FireworkExplodeEvent extends EntityEvent implements Cancellable {
+
+    private static final HandlerList handlers = new HandlerList();
+    private boolean cancel;
+
+    public FireworkExplodeEvent(final Firework what) {
+        super(what);
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return cancel;
+    }
+
+    /**
+     * Set the cancelled state of this event. If the firework explosion is
+     * cancelled, the firework will still be removed, but no particles will be
+     * displayed.
+     *
+     * @param cancel whether to cancel or not.
+     */
+    @Override
+    public void setCancelled(boolean cancel) {
+        this.cancel = cancel;
+    }
+
+    @Override
+    public Firework getEntity() {
+        return (Firework) super.getEntity();
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+}