ui: administration: set icons for tabs

orient on PVE, the ones for Updates, ServerStatus, should by
self-explanatory.

Services is in PVE named "System", but reusing that cogs icon makes
similar sense here too, and seems in line with search result of a
"service icons" query.

Syslog is the same as our general log icon, but as we also use this
normally for worker task logs and that is present here too, I
changed the worker task log icon to the alternative list, which
resembles a task view window - so IMO even better than before.

Sync that change also into the always present tasks button at the top
right.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

www/button/TaskButton.js

@@ -7,7 +7,7 @@ Ext.define('PBS.TaskButton', {
 	badgeCls: '',
     },
 
-    iconCls: 'fa fa-list',
+    iconCls: 'fa fa-list-alt',
     userCls: 'pmx-has-badge',
     text: gettext('Tasks'),