Improve Latest Data performance

Opening Latest data page takes too long to load, when opening it with checkbox "Show items without data" unchecked.

The reason for this performance problem is that frontend needs to check data availability for each filtered item in system.

Proposed solution: This heavy request should be performed only on narrowed selection, specifically - only when specific hosts are selected in filter. If there are no hosts selected in filter, the checkbox "Show items without data" should be checked and disabled.