Refactor Userwall #78

Refactor the userwall so it has two different modes, one to show only photos and one to show everything.

• In the overview, "SHOW ALL ENTRIES" shows all posts, regardless of the additional message, photo or name
• with "SHOW ONLY PHOTOS" only entries with photos are shown in the overview
  Applies to BOTH viewing modes: ALL posts that contain a message are displayed in the LIGHTBOX
  See picture with name and flag etc ...
• With "SHOW ALL ENTRIES", entries without a photo, name or message are also displayed because the COUNTRY is a mandatory field and this entry can therefore still be displayed. E.g. see draft by showing an entry in the overview with human + flag.
• With the "Show all entries" filter, the flag should always be displayed in the posts in the overview. With "only show photos" it stays clean, without flag or name / person