Fixes ISSUE-44932: Allow scheduling a process without start date or time
Previously it was possible to schedule a process without start date or time, assuming current date and current time. This was lost in a refactor. A new method getCurrentDateTime has been added to SchedulerTimeUtils to get the missing part of date/time provided assuming "now" when missing. It will return the date + time in the expected format for timestamp and parse.
Fixes regression introduced in commit dded7dec