Add a severity filter, much like it is present in various
places in Zabbix, as well as a filter for the acknowledgement
status. This brings the interface closer to what is asked for
in https://support.zabbix.com/browse/ZBXNEXT-410
A new checkbox in the annotation configuration form allows
to prefix the hostname to the title used in the annotation.
This option is relevant for people not stating the hostname
in their triggers. Within Zabbix, the hostname would be shown
redundantly everywhere, except in notifications.
