Create Notification database and Notification repository struct skeleton.

src/repository/mod.rs

+pub mod notification;
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src/repository/notification.rs

+use std::sync::RwLock;
+ 
+ use lazy_static::lazy_static;
+ 
+ use crate::model::notification::Notification;
+ 
+ // Singleton of Database
+ 
+ lazy_static! {
+     static ref NOTIFICATIONS: RwLock<Vec<Notification>> = RwLock::new(vec![]);
+ }
+ 
+ pub struct NotificationRepository;
+ 
+ impl NotificationRepository {
+ }
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