Replace Google Maps with static images

[roskakori]

User story

As visitor I want view the map of the location of a meeting with my IP to remain private instead of being submitted to Google in order to be in control of my data.

Goals

• Each location can have a static image of the map attached to it.
  • By default, a location has no image.
• An admin can attach an image to a location in the Django admin.
• On the meetup, the image of the location is shown.
  • The the location has no image, this part of the page is empty.

Design consideration

We could also change Google Maps to Open Stream Maps. But this takes more effort than static images, and would also require a cookie banner.