feat(core/database): basic implementation of User and File models

crates/core/database/src/drivers/reference.rs

@@ -2,12 +2,13 @@ use std::{collections::HashMap, sync::Arc};
 
 use futures::lock::Mutex;
 
-use crate::Bot;
+use crate::{Bot, User};
 
 database_derived!(
     /// Reference implementation
     #[derive(Default)]
     pub struct ReferenceDb {
         pub bots: Arc<Mutex<HashMap<String, Bot>>>,
+        pub users: Arc<Mutex<HashMap<String, User>>>,
     }
 );