[Feature Request] Retroactively disable people's hidden status

[Folas1337]

We've previously discussed this topic on the Discord server but so far it hasn't made its way into the plugin yet.

Here's the proposed solution from @BillyGalbreath

Only downside this implementation would have is if someone is using a custom system to hide people, for example through a command or the API which isn't being addressed but I personally don't need it so for me it can be ignored :)