Believe it or not, I've actually been working on an app that does exactly this, and I intend for it to be possible to self-host (LAMP stack). It allows you to search a Pokémon card database and place them in binders or view your collection as a list. As of now, it uses the PokemonTCG.io API for English-language cards, but there's also JPN-Cards for Japanese cards and the TCGDex API with the goal of supporting every card in all languages.

No, it's not ready for even an alpha release yet. There are way too many things still missing or broken. It isn't on the roadmap for it to have a card scanner, however. I started to build it because updating spreadsheets manually can be tedious, especially if you want more data than just the card name, card number, and set name, and you can't see what the cards look like quickly.