Add new snippet to get UTC datetime

[daipresents]

For example, if a user in Japan runs a mabl test locally, the time zone will be JST.
However, mabl cloud execution is in the US environment, so the time zone will be UTC.
Thus, there is a difference between the local and cloud environments.

This snippet is a sample that converts a date/time string in a specified local time zone to UTC.

Since it works only in the mabl cloud environment, the local date and time is converted to UTC in the cloud execution, pseudo-absorbing the environment difference.