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

server/middlewares/methodOverride.ts

@@ -0,0 +1,19 @@
+import { Context } from "koa";
+import queryString from "query-string";
+
+export default function methodOverride() {
+  return async function methodOverrideMiddleware(
+    ctx: Context,
+    next: () => Promise<any>
+  ) {
+    if (ctx.method === "POST") {
+      ctx.body = ctx.request.body;
+    } else if (ctx.method === "GET") {
+      ctx.method = 'POST'; // eslint-disable-line
+
+      ctx.body = queryString.parse(ctx.querystring);
+    }
+
+    return next();
+  };
+}