Bug 8287: Improve "show checked out items" filter on the overdues report

Bug 8287: Improve "show checked out items" filter on the overdues report

The "Show any items currently checked out" was confusing, especially if
the "From" and "To" due date filters were passed.

This patch moves the checkbox close to the 2 other filters and show/hide
the due date filters when needed.

Test plan:
0. Have some overdue
1. Search for overdues
2. Confirm that the filters are shown/hidden depending on the status of
the checkbox
3. Fill "To" with a date, tick the checkbox, submit the form
=> Confirm that the date was not taken into account

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>