[feature]: Cover images for issue cards previews

Is there an existing issue for this?

• I have searched the existing issues

Summary

Include an option to add cover images (or display the first added in description) to issue cards for a quick visual preview. This is especially relevant for Kanban Layout. I got a mockup here:
![plane-imagecover](


Why should this be worked on?

Especially for design-oriented teams, it is super helpful to have quick visual overviews of the different tasks. Production environments also often work with IDs or SKUs that aren't particularly descriptive so having a visual of an engineering element, chair design, UI mockup etc. is essential.