SPIGOT-7540, #946: Add ServerTickManager API

By: Miles Holder <mwholder2005@gmail.com>

paper-api/src/main/java/org/bukkit/Bukkit.java

@@ -280,6 +280,16 @@ public final class Bukkit {
         return server.getDataPackManager();
     }
 
+    /**
+     * Get the ServerTick Manager.
+     *
+     * @return the manager
+     */
+    @NotNull
+    public static ServerTickManager getServerTickManager() {
+        return server.getServerTickManager();
+    }
+
     /**
      * Gets the server resource pack uri, or empty string if not specified.
      *