Original PR description

Behaviour prior to fix:
Whenever we used any of the buttons in the planning front-end we would get a page no found error when being redirected.

Cause:
The planning and employee tokens could not be fetched from the DOM as we did before because the calendar view was not properly rendered with the update to FC v6. This lead to the tokens being undefined when clicking the buttons and thus the redirect leading to the page-not- found errors.

Fix:
Changed the element that we mount to the FC to more specifically be the calendar widget. That way DOM of the  calendar post render more closely resembles what it looked like before the update to v6 and thus the buttons work again.

task-3791067