DatePicker: specify time zone for today's date (current)

Describe the enhancement or change

We propose adding a property to the DatePicker (and CalendarMonth) components to specify the time zone to be applied when determining today's date.

Details
In our application, users can specify the time zone they are working in.

For instance, a user located in the PST time zone may collaborate with users in the UK and choose to use the UTC time zone within the application.
If the user sets the time zone to UTC (01:02, 21 November), the application may still highlight the 20th because it reflects the local date based on the user's computer settings rather than the selected UTC time zone (17:02, 20 November).

When the user changes their computer’s clock to UTC, then the today's date is updated to the 21st as expected.

Is this request originating from a Red Hat product team? If so, which ones and is there any sort of deadline for this enhancement?
No

Any other information?

Link to hardcoded today's date: https://github.com/patternfly/patternfly-react/blob/main/packages/react-core/src/components/CalendarMonth/CalendarMonth.tsx#L122

从 packages/react-core/src/components/CalendarMonth/CalendarMonth.tsx 中硬编码的今天日期附近开始，然后跟踪 DatePicker 和 CalendarMonth 如何确定当前日期。根据 issue 中的 UTC 示例定义时区属性的行为，并验证今天日期的高亮遵循所选时区，而不是计算机的本地设置。