Add 'permission clear' command (#893)

api/src/main/java/me/lucko/luckperms/api/Node.java

@@ -291,6 +291,14 @@ public interface Node {
     @Nonnull
     ContextSet getFullContexts();
 
+    /**
+     * Returns if the node is a "standard" permission node.
+     *
+     * @return true if this is a regular permission node
+     * @since 4.2
+     */
+    boolean isRegularPermissionNode();
+
     /**
      * Returns if this is a group node.
      *