Change activity text while loading metadata
After log in into webui there was 'Authenticating' sign even during loading metadata.
Now while data are loading there is 'Loading data' text. This change requires new global
topic 'set-activity' of activity widget. So for now there is possibility to change
every activity string during running phase just by publishing 'set-activity' topic
and setting new text as first parameter.
Part of: https://fedorahosted.org/freeipa/ticket/6144
Reviewed-By: Petr Vobornik <email@example.com>