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/errors.ts

@@ -0,0 +1,17 @@
+import ExtendableError from "es6-error";
+
+export class AuthorizationError extends ExtendableError {}
+
+export class BadRequestError extends ExtendableError {}
+
+export class NetworkError extends ExtendableError {}
+
+export class NotFoundError extends ExtendableError {}
+
+export class OfflineError extends ExtendableError {}
+
+export class ServiceUnavailableError extends ExtendableError {}
+
+export class RequestError extends ExtendableError {}
+
+export class UpdateRequiredError extends ExtendableError {}