Add placeholder to add segment dialog

'Autogenerated' placeholder is shown when adding new segment.

https://fedorahosted.org/freeipa/ticket/5867

Reviewed-By: Petr Vobornik <pvoborni@redhat.com>

install/ui/src/freeipa/topology.js

@@ -865,6 +865,7 @@ topology.create_add_dialog = function(spec) {
     spec.fields = spec.fields || [
         {
             name: 'cn',
+            placeholder: '@i18n:objects.topology.autogenerated',
             required: false
         },
         {

install/ui/test/data/ipa_init.json

@@ -600,6 +600,7 @@
                             "user": "Who"
                         },
                         "topology": {
+                            "autogenerated": "Autogenerated",
                             "segment_details": "Segment details",
                             "replication_config": "Replication configuration",
                             "insufficient_domain_level" : "Managed topology requires minimal domain level ${domainlevel}"

ipaserver/plugins/internal.py

@@ -739,6 +739,7 @@ class i18n_messages(Command):
                 "user": _("Who"),
             },
             "topology": {
+                "autogenerated": _("Autogenerated"),
                 "segment_details": _("Segment details"),
                 "replication_config": _("Replication configuration"),
                 "insufficient_domain_level" : _("Managed topology requires minimal domain level ${domainlevel}"),