tasks #7440: make tracker workflow rules work with datetime

- if one of the fields has only date but no time, compare the date
- in all other cases compare datetime

Change-Id: I36911bf9a7040ccc8d3dd554e00244f160684729
Merge commit 'refs/changes/00/3000/5' of ssh://gerrit.tuleap.net:29418/tuleap into HEAD

* ssh://gerrit.tuleap.net:29418/tuleap:
  tasks #7440: make tracker workflow rules work with datetime

Change-Id: Idd7a4d3cc01d39ce1872af22e3ba9e8021348c47
This is Tuleap 7.4.99.32

Change-Id: Ifac205aebb21347ee161896e69c6a3c515114e28