Bug 13601: get rid of DateTime::Format::DateParse

Bug 13601: get rid of DateTime::Format::DateParse

This module is used in C4::Members::GetPendingIssues too, but we can use
dt_from_string.

Test plan:
1/ Verify that
    prove t/db_dependent/Members/GetPendingIssues.t
returns green
2/ On the patron pending issue list, verify that the issue and the due
dates are correctly displayed.

Tested together with other patches (except "Fix special cases). Worked as expected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>