Convert ManageEvent Fees to datepicker

[mattwire]

Overview

Convert form to use datepicker:
Manage Event - Fees.

Partial from #12973

Before

Using old jcalendar.

After

Using "new" datepicker.

[civibot]

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[eileenmcnaughton]

I tested this & it was pretty painful to work with this in the UI - but this PR does not alter that for the better or the worse. I read through the code & the changes all appear correct and the overall attempt to remove remaining instances of jcalendar is an ongoing one - which finally seems within reach - down with CRM_Utils_Date::setDateDefaults long live datepicker