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/hooks/usePageVisibility.ts

@@ -0,0 +1,20 @@
+import * as React from "react";
+/**
+ * Hook to return page visibility state.
+ *
+ * @returns boolean if the page is visible
+ */
+
+export default function usePageVisibility(): boolean {
+  const [visible, setVisible] = React.useState(true);
+
+  React.useEffect(() => {
+    const handleVisibilityChange = () => setVisible(!document.hidden);
+
+    document.addEventListener("visibilitychange", handleVisibilityChange);
+    return () => {
+      document.removeEventListener("visibilitychange", handleVisibilityChange);
+    };
+  }, []);
+  return visible;
+}