HOR-4075

Define Interface for List classes.
Implement a trait base for the lists.
Fix sort by current user at Review and Reassign lists.

workflow/engine/classes/ListUserDisplayFormatInterface.php

@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * The list implements user name formated.
+ *
+ */
+interface ListUserDisplayFormatInterface
+{
+
+    /**
+     * Get the $userDisplayFormat value.
+     *
+     * @return string
+     */
+    public function getUserDisplayFormat();
+
+    /**
+     * Set the value of $userDisplayFormat.
+     *
+     * @param string $v new value
+     * @return void
+     */
+    public function setUserDisplayFormat($v);
+}