EventgridQuery: Make filter column `hostgroup' case-insensitive

...and add a case-sensitive query column.

refs #8613

modules/monitoring/library/Monitoring/Backend/Ido/Query/EventgridQuery.php

@@ -35,7 +35,8 @@ class EventgridQuery extends IdoQuery
         ),
 
         'hostgroups' => array(
-            'hostgroup'  => 'hgo.name1'
+            'hostgroup'         => 'hgo.name1 COLLATE latin1_general_ci',
+            'hostgroup_name'    => 'hgo.name1'
         )
     );
 

modules/monitoring/library/Monitoring/DataView/Eventgrid.php

@@ -47,6 +47,6 @@ class Eventgrid extends DataView
 
     public function getFilterColumns()
     {
-        return array('host', 'service');
+        return array('host', 'service', 'hostgroup');
     }
 }