Canvis a "Ability for users to withdraw their meetings"

Is your feature request related to a problem? Please describe.
Now that users can create meetings they don't have a way to withdraw them if the event is canceled.

Describe the solution you'd like
As a logged in user when visiting the meeting I have a button to withdraw my event.

As a loggued in user I can access the list of withdrawn meetings by clicking on link from the meeting index.

When accessing the view with the withdrawn meetings, the meetings card display a red withdawn label. If there are many withdrawn meetings the index uses pagination.

A banner explains the filtered a view and provides a link to go back to the original index.

A button is displayed at the button of index to go back to the original view.

Withdrawn meetings have the same behaviour as withdrawn proposals :

• Withdrawn meetings display on users activity page.
• Withdrawn meetings do not display in the meeting index search results
  
• Withdrawn meetings are not computed in the statistics block.
• Withdrawn meetings are taken into account in the metrics block.

A field is added to the meeting schema on the GraphQL API `isWithdrawn = boolean!`

Additionnal context

Admin can unpublish their meetings since this PR : https://github.com/decidim/decidim/pull/7893

Does this issue could impact on users private data?
No

Funded by
EU Commission