SPIGOT-5380, SPIGOT-6958, #772: Add some missing entity API

By: Ollie <69084614+olijeffers0n@users.noreply.github.com>

paper-api/src/main/java/org/bukkit/entity/Ghast.java

@@ -3,4 +3,19 @@ package org.bukkit.entity;
 /**
  * Represents a Ghast.
  */
-public interface Ghast extends Flying {}
+public interface Ghast extends Flying {
+
+    /**
+     * Gets whether the Ghast is charging
+     *
+     * @return Whether the Ghast is charging
+     */
+    boolean isCharging();
+
+    /**
+     * Sets whether the Ghast is charging
+     *
+     * @param flag Whether the Ghast is charging
+     */
+    void setCharging(boolean flag);
+}