Bug 14923: Remove C4::Dates from labels/label-item-search.pl

Bug 14923: Remove C4::Dates from labels/label-item-search.pl

This patch removes C4::Dates from labels/label-item-search.pl

To test:
- Go to Home > Tools > Labels home > Manage label batches
- Click "Add item(s)"
- Verify that selection with date after and date before works
  the same as without patch.

Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
Works as advertised. Tested with bad dates

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Todo later: Some checks should be added on client side.
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>