Added filters for notifications and system tray items. (#234)

* Added filters for notifications and systray. closes #233

* Add links to documentation.

lib/shared/notifications.ts

@@ -0,0 +1,15 @@
+import { Notification } from "types/service/notifications";
+
+export const filterNotifications = (notifications: Notification[], filter: string[]): Notification[] => {
+
+    const notifFilter = new Set(
+        filter.map((name: string) => name.toLowerCase().replace(/\s+/g, '_'))
+    );
+
+    const filteredNotifications = notifications.filter((notif: Notification) => {
+        const normalizedAppName = notif.app_name.toLowerCase().replace(/\s+/g, '_');
+        return !notifFilter.has(normalizedAppName);
+    });
+
+    return filteredNotifications;
+}