chore: Move to Typescript (#2783)

This PR moves the entire project to Typescript. Due to the ~1000 ignores this will lead to a messy codebase for a while, but the churn is worth it – all of those ignore comments are places that were never type-safe previously.

closes #1282

app/test/setup.ts

@@ -0,0 +1,16 @@
+/* eslint-disable */
+// @ts-expect-error ts-migrate(7016) FIXME: Could not find a declaration file for module '../.... Remove this comment to see the full error message
+import localStorage from "../../__mocks__/localStorage";
+import Enzyme from "enzyme";
+import Adapter from "enzyme-adapter-react-16";
+import { initI18n } from "@shared/i18n";
+
+initI18n();
+
+Enzyme.configure({
+  adapter: new Adapter()
+});
+
+global.localStorage = localStorage;
+
+require("jest-fetch-mock").enableMocks();