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/utils/language.ts

@@ -0,0 +1,16 @@
+export function detectLanguage() {
+  const [ln, r] = navigator.language.split("-");
+  const region = (r || ln).toUpperCase();
+  return `${ln}_${region}`;
+}
+
+export function changeLanguage(
+  toLanguageString: string | null | undefined,
+  i18n: any
+) {
+  if (toLanguageString && i18n.language !== toLanguageString) {
+    // Languages are stored in en_US format in the database, however the
+    // frontend translation framework (i18next) expects en-US
+    i18n.changeLanguage(toLanguageString.replace("_", "-"));
+  }
+}