Rethink "Continue existing application" functionality

**Background:**

The "Continue existing application" area on the Catalogue page currently shows drafts for the applicant. One idea is that maybe it should contain also the applications that require the applicants attention like the open todo list on actions page lists all the applications that require a handler's attention. Also it should actually list the open applications for the members and not just for the applicant.

On the other hand, a simple solution would be to only show a link to the applications page where the list already exists. It would make the whole Catalogue page simpler and cleaner.

We could also make sure the intro text is actually helpful.

A final consideration is to have a separate front-page and not use the Catalogue page like this.

**Tasks:**

Let's try by simplifying the Catalogue page because it simplifies our application.

- [ ] show a simplified pointer to the Applications page, if there are drafts or returned applications (or maybe even applications requiring you to accept licenses)
- [ ] do not show the table anymore
- [ ] show the link for the members as well as the applicant
- [ ] make sure the intro text is actually helpful (now it is short and does not add value)

Start by locating the Catalogue page and its existing "Continue existing application" area, then compare it with the Applications page and the actions-page todo list. Check how drafts, returned applications, license acceptance, applicants, and members are represented. Done means the table is removed, the appropriate pointer and helpful introductory text are shown for both roles, and the stated application states are covered.

Written by the indexing model from the issue text.