Enable card images for debates

Is your feature request related to a problem? Please describe.
The debates module does not allow any card images and is therefore very text-heavy and unappealing on the overview page.

Describe the solution you'd like
Like on the proposal page, I would enable the upload of a card image.

Describe alternatives you've considered
I've tried using decidim awesome and uploading an image through the description text. However, the image is not displayed on the overview page.

Additional context
–

Does this issue could impact on users private data?
–

Funded by
Funding available through the City of Zürich.