Groups: Thumbnail images and groups page header images are too big #7761
Description
The thumbnail images and groups page header images are huge. They are not downscaled like other images, e.g. on the front page. Images here are in the original size that people upload them, e.g. if anyone uploads a 6MB image that image will appear. In other areas of the system we use the thumbnail version of images. This should be used here as well and the top image should also be a downscaled image.
Compare: https://eventyay.com/my-groups/list and https://eventyay.com/g/40
