feat(datepicker): unlinked calendars

[Maxie42]

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Summary

This feature adds the option to enable changing the calendars separately on the daterange picker. When enabled each calendar has it's own state and any changes that happen will be done on that, without affecting the other calendars.

A new config option has been added unlinkedCalendars By default it's false, so it works as it did before.

Below are some screenhots showing it in action:

PR Checklist

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• read and followed the CONTRIBUTING.md guide.
• built and tested the changes locally.
• added/updated tests.
• added/updated API documentation.
• added/updated demos.