[API] Verify tags

[spifory]

When tags are being posted to the /previews route, they should have some sort of check to see if they are actual OG/Meta tags, and not just a way for people to add anything they want. This should preferably use some sort of package because I'm lazy to do it myself because it would just be more simpler to do it that way.

Something quite similar to opengraph-writer using python, but of course using an NPM package since the API uses TypeScript.