Support datetime format for triggers of valarm

[AustinZhang1024]

The problem

Support trigger like this:

BEGIN:VALARM
TRIGGER:20250114T133635Z
ACTION:DISPLAY
DESCRIPTION:On time reminder
END:VALARM

It reports Error: invalid duration value: Not enough duration components in "133635Z"

Related issue: #120 Related code: https://github.com/derekantrican/GAS-ICS-Sync/blob/e0f8c14ffc8ebadcba9e12fc9307c789f83367af/Helpers.gs#L796-L796

https://github.com/derekantrican/GAS-ICS-Sync/blob/e0f8c14ffc8ebadcba9e12fc9307c789f83367af/ical.js.gs#L715-L730

Version of GAS-ICS-Sync

5.8

Additional information & file uploads

No response