R1:a04af2a9eeee

Calendar event datepicker should auto-complete end time to be an hour from start time unless end time has been edited.

Summary: Ref T8031, Calendar event datepicker should auto-complete end time to be an hour from start time unless end time has been edited

Test Plan: Create event, edit start time, end time should adjust to an hour from start time.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Maniphest Tasks: T8031

Differential…