fix(date-picker): let Flatpickr parse date instead of doing it with new Date() (#431)
fix(date-picker): let Flatpickr parse date instead of doing it with new Date() (#431)

JavaScript Date constructor does not have proper i18n support when a string is given.
You'll see a very ambiguous spec at: https://www.ecma-international.org/ecma-262/6.0/#sec-date.parse
In the particular case of #396, `new Date()` seems to think `Y-m-d` format as an ISO8601 UTC-based string,
whereas `Y/m/d` seems to be treated as a locale-specific, local-timezone-based string.
It ends up with producing a date object for the former case, that is of six hours before the clock for users in Austin,
and thus one day off for the date part.

Fixes #396.
carbon-design-system/carbon-components,carbon-design-system/carbon-components,carbon-design-system/carbon-components