Ability to import and expose pin metadata

[Toastbrot236]

This would be very useful for exposing pin data over the API.

This would involve reading files like https://github.com/LittleBigRefresh/Docs/blob/main/Docs/pin-files/lbp3.json and then probably importing the metadata into the database, so the file wouldn't have to be read every time the server needs the metadata (or atleast everytime the server starts, in which case all the metadata would have to be kept in memory, which is not a good idea).