refactor: split anki-connect and stats-server resolvers into modules (#169)

src/config/resolve/anki-connect/shared.ts

@@ -0,0 +1,9 @@
+import { isNotificationType, type NotificationType } from '../../../types/notification';
+
+export function asNotificationType(value: unknown): NotificationType | undefined {
+  return isNotificationType(value) ? value : undefined;
+}
+
+export function hasOwn(obj: Record<string, unknown>, key: string): boolean {
+  return Object.prototype.hasOwnProperty.call(obj, key);
+}