Refactor the db; move to *Manager classes

web/src/app/UserManager.js

@@ -0,0 +1,22 @@
+import db from "./db";
+
+class UserManager {
+    async all() {
+        return db.users.toArray();
+    }
+
+    async get(baseUrl) {
+        return db.users.get(baseUrl);
+    }
+
+    async save(user) {
+        await db.users.put(user);
+    }
+
+    async delete(baseUrl) {
+        await db.users.delete(baseUrl);
+    }
+}
+
+const userManager = new UserManager();
+export default userManager;