Mock YdtBuilder and YdtNode to do UT for Restconf

fix the java code problems.
add more test cases

Change-Id: I034d35e8a41a6c12e293fad867d6540dd5f37e95
diff --git a/protocols/restconf/server/utils/src/test/resources/listAfterLeaflist.json b/protocols/restconf/server/utils/src/test/resources/listAfterLeaflist.json
new file mode 100644
index 0000000..bbe25e1
--- /dev/null
+++ b/protocols/restconf/server/utils/src/test/resources/listAfterLeaflist.json
@@ -0,0 +1,12 @@
+{
+  "leaf-identifier1": "1",
+  "leaf-list-identifier1": [
+    "5",
+    "12"
+  ],
+  "list-identifier1": [
+    {
+      "leaf-identifier2": "5"
+    }
+  ]
+}
\ No newline at end of file