Hello,
I do a camera snapshot each time somebody rings on my front door bell. These snapshots are stored locally as files in a dedicated folder. Is there any way I can read the files from that folder and build a list of them to render on the UI? Ideally, the date and time should be rendered in the list items, and then on click, the image should be shown in a popup, like cameras do it. I know this isn’t existing out of the box, but any ideas how to accomplish it are more than welcome!
Anyone any ideas? 
I have never seen a custom card or component do what you’re trying to do. You may have to rethink or scale down your approach, or if you’re an experienced programmer, then try coding a custom camera.
You could use the local file camera component to load a specific image. If you replace that specified image with the latest snapshot from your doorbell, then you have a limited solution at least.
If you want to view the most recent video, I would take a look at the Xiaomi component code to see how HA connects to the camera’s FTP server to pull the latest video. I would look at that as a starting point if you want to create a custom camera.