fix(ZMS-3253 ZMS-3466 ZMS-3415 ZMS-1891): Replicate frontend validation in the backend for the availability opening hours to improve data integrity and frontend validation messaging#812

ThomasAFink wants to merge 130 commits intonextit-at-m/eappointment:nextfrom

bugfix-zms-3253-3466-3415-1891-validation-opening-hours-of-the-same-appointment-type-must-not-overlapit-at-m/eappointment:bugfix-zms-3253-3466-3415-1891-validation-opening-hours-of-the-same-appointment-type-must-not-overlapCopy head branch name to clipboard