fix email length check, add unenroll api+email system

.bruno/User Endpoints/unenroll user.bru

@@ -0,0 +1,24 @@
+meta {
+  name: unenroll user
+  type: http
+  seq: 3
+}
+
+delete {
+  url: http://localhost:14014/api/unenroll
+  body: json
+  auth: inherit
+}
+
+body:json {
+  {
+    "name": "test",
+    "pin": "1234",
+    "deleteCode": ""
+  }
+}
+
+settings {
+  encodeUrl: true
+  timeout: 0
+}