Add DDNS support (#324)

* feat: add ddns updater framework

Note: no functionality implemented yet

* feat: add webhook ddns provider

* feat: update dashboard template

* fix: check nil and cron task string

* fix: webhook string formated with unexcepted param

* fix: webhook header split error

* feat: cloudflare ddns provider

* refract: move ddns update trigger into ReportSystemInfo

* lang: update other languages text

* fix: clear codes and logics

* fix: move update ddns to goroutine to avoid blocking

* fix: clear unused codes

* fix: update timestamp to prevent cache

resource/template/component/server.html

@@ -26,6 +26,16 @@
                     <label>{{tr "HideForGuest"}}</label>
                 </div>
             </div>
+            <div class="field">
+                <div class="ui enableddns checkbox">
+                    <input name="EnableDDNS" type="checkbox" tabindex="0" />
+                    <label>{{tr "EnableDDNS"}}</label>
+                </div>
+            </div>
+            <div class="field">
+                <label>{{tr "DDNSDomain"}}</label>
+                <input type="text" name="DDNSDomain" placeholder="{{tr "DDNSDomain"}}">
+            </div>
             <div class="field">
                 <label>{{tr "Note"}}</label>
                 <textarea name="Note"></textarea>