As a user,
I want to be sure that my intention to apply for a membership is honored and not canceled inadvertently.
Acceptance Criteria:
- Route cancel-membership-application is only possible with POST
- Template(s) where the route is used, are adapted
Background:
GET URLs should not trigger side effects on the server. While this is not a problem at the moment, future browsers might try to pre-load the "cancel-membership-application" URL when loading the confirmation page.