CSV/JSON export ignores filter

[sukhwinder33445]

Describe the bug

Trying to export filtered hosts/services/groups/* ignores the filter and export all objects.

To Reproduce

Provide a link to a live example, or an unambiguous set of steps to reproduce this issue. Include configuration, logs, etc. to reproduce, if relevant.

1. Add a filter to host list, for example host.name=EXISTING_HOST_NAME.
2. Export it to CVS/JSON
3. Have a look into the exported file.

Expected behavior

Only the filtered objects should be exported.

Additional context

The filter is not applied to the csv/json tab url.

[nilmerg]

This is broken since Icinga/ipl-web#195 and is likely to be fixed there as well. (Any caller of getParams() is affected as long as the desired result was a complete query string)