[Feature Request] Download media covers to server

[BraianPita]

Describe the solution you'd like
I noticed the web client just displays whatever image I added to a custom media entry on my list, which can cause covers to stop working if the original source ever disappears or the URL changes. To avoid this, I would like the images to be downloaded and served from the Yamtrack server instead.

Describe alternatives you've considered
It could also be an option that you can opt-in/opt-out or you can choose to download the cover to the server from the media details page.

Additional context
Notice that when I inspect the image, the url points to the original source, which means the link can break and the cover would be lost.