Monitoring/ListController: Operate on the `hostStatus' view instead of the query

The monitoring module's ListController should only operate on data views instead of queries.
Thus the applyRestrictions() method now expects a data view instead of a query. Further since
filters are subject to change the applyRestrictions() method now does nothing.

The `hostsAction()' no longer uses `DataView::fromRequest()' but selects the data view from
a monitoring backend. `DataView::fromRequest()' orders the underlying query which must be reworked
in the current scenario.