[JS] Implement localized datepicker for date fields

[alariva]

Date fields should be helped with a JS datepicker component.

However, so far the implementation approaches have brought problems with localization and date format.

• English date format m/d/yyyy
• Spanish date format d/m/yyyy

The user should be able to view and pick dates in his preferred (familiar) format according to the localization language. Then the dates should be translated accordingly for form submissions.

Example of desired result: