Refactor alerts to TypeScript, remove react-notification dependency (#34239)

app/javascript/mastodon/models/alert.ts

@@ -0,0 +1,14 @@
+import type { MessageDescriptor } from 'react-intl';
+
+export type TranslatableString = string | MessageDescriptor;
+
+export type TranslatableValues = Record<string, string | number | Date>;
+
+export interface Alert {
+  key: number;
+  title?: TranslatableString;
+  message: TranslatableString;
+  action?: TranslatableString;
+  values?: TranslatableValues;
+  onClick?: () => void;
+}