feat(components): add gs-date-range-changed event to date range selector

[JonasKellerer]

Resolves #81, resolves #80

Summary

This adds a event and a submit button to the date range selector. The event contains the dateFrom and dateTo of the selector.

Screenshot

PR Checklist

• [x] The implemented feature is covered by an appropriate test.

[JonasKellerer]

As discussed we remove the submit button and submit, when the user

• hits enter
• selects one from the predetermined ranges
• leaves the component

[JonasKellerer]

The component now looks like this without the submit button: