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/models/Policy.ts

@@ -0,0 +1,9 @@
+import BaseModel from "./BaseModel";
+
+class Policy extends BaseModel {
+  id: string;
+
+  abilities: Record<string, boolean>;
+}
+
+export default Policy;