ui: add selectUser api

packages/ui-default/templates/home_messages.html

@@ -1,20 +1,5 @@
 {% extends "layout/home_base.html" %}
 {% block home_content %}
-<div style="display: none" class="dialog__body--user-select">
-  <div>
-    <div class="row"><div class="columns">
-      <h1>{{ _('Select User') }}</h1>
-    </div></div>
-    <div class="row">
-      <div class="columns">
-        <label>
-          {{ _('Username / UID') }}
-          <input name="user" type="text" class="textbox" autocomplete="off" data-autofocus>
-        </label>
-      </div>
-    </div>
-  </div>
-</div>
 <div class="section">
   <div id="messagePad">
     {{ noscript_note.render() }}