initial commit
- extracted context Appointment from basic-base
- extracted context AppointmentAttendees from basic-base
- extracted context AppointmentLink from basic-base
- extracted Calendar_Lib as CalendarUtils_lib from basic-base
- extracted Appointment_Lib as AppointmentUtils_lib from basic-base
- added Appointent_Data_alias with liquibase changelob for 'AB_APPOINtMENTLINK'
- added ExtensionPoint for actions in the Appointment_entity
- added respective serviceDefineitions for onInit, onUpdate and onDelete int the Appointment_entity